I’ve been obsessed with these chicken and spinach stuffed portobello mushrooms ever since I first made them on a busy weeknight! Those meaty portobello caps make the perfect edible bowls for a savory filling packed with tender chicken, wilted spinach, and plenty of garlic and parmesan. Trust me, once you try these, they’ll become a regular in your dinner rotation.
| Preparation Time | 20-25 minutes |
| Cooking Time | 30-40 minutes |
| Total Time | 50-65 minutes |
| Level of Difficulty | Medium |
| Servings | 6 servings |
Estimated Nutrition
Estimated nutrition for the whole recipe (without optional ingredients):
- Calories: 1400-1550
- Protein: 120-135 g
- Fat: 75-90 g
- Carbohydrates: 65-80 g
Ingredients
For the mushrooms:
- 6 large portobello mushroom caps (stems and gills removed)
- 1/4 teaspoon salt
- 1/4 teaspoon black pepper
For the filling:
- 1 lb chicken (finely diced into 1/4-inch pieces)
- 10 oz spinach (wilted, squeezed very dry, and chopped)
- 1/2 cup parmesan cheese (Sartori Classic preferred)
- 1 small onion (finely minced)
- 1 egg (lightly beaten)
- 8 cloves garlic (minced)
- 1/3 cup fresh parsley (chopped)
- 3/4 tsp onion powder
- 1 tsp salt
- 1 tsp pepper
- 1/2 tsp dried oregano
- 1/4 tsp red pepper flakes
For the topping and sauce:
- 2 cups marinara sauce (such as Rao’s Homemade)
- 6 oz mozzarella (shredded or sliced for extra melt)
- 2 tablespoons fresh parsley (for garnish)
Step 1: Prepare Mise en Place and Wilt the Spinach
- 10 oz spinach
- 8 cloves garlic
- 1 small onion
- 1 lb chicken
- 1/3 cup fresh parsley
Start by wilting the spinach in a large skillet over medium heat, stirring occasionally until completely wilted (about 3-4 minutes).
Transfer to a fine-mesh strainer or colander and squeeze very firmly with your hands or the back of a spoon to remove as much liquid as possible—this is crucial for preventing a watery filling.
Chop the squeezed spinach finely and set aside.
While the spinach cools slightly, mince the garlic and onion as finely as possible, chop the fresh parsley, and dice the chicken into small, uniform 1/4-inch pieces.
Having everything prepped before you start cooking ensures the filling comes together quickly.
Step 2: Prepare the Mushrooms for Roasting
- 6 large portobello mushroom caps
- Parchment paper
Preheat your oven to 450°F and line a large baking sheet with parchment paper.
Clean the portobello mushroom caps with a damp cloth and use a small spoon to gently scrape out and remove the dark gills from the underside—this prevents the mushrooms from releasing too much moisture during cooking.
Remove the stems as well.
Place the mushroom caps gill-side up on the prepared baking sheet, then roast for 10 minutes.
After 10 minutes, carefully flip them over (gill-side down) and roast for another 5 minutes.
This initial roasting helps render some of the mushroom's moisture and sets the caps.
Step 3: Build the Chicken and Spinach Filling
- 1/2 cup parmesan cheese
- 1/3 cup fresh parsley
- 1 small onion
- 1 egg
- 8 cloves garlic
- 3/4 tsp onion powder
- 1 tsp salt
- 1 tsp pepper
- 1/2 tsp dried oregano
- 1/4 tsp red pepper flakes
- wilted spinach from Step 1
- 1 lb chicken from Step 1
Remove the mushrooms from the oven and carefully pour out any accumulated liquid from the pan.
In a medium bowl, combine the parmesan cheese, chopped parsley, minced onion, lightly beaten egg, minced garlic, onion powder, salt, pepper, dried oregano, and red pepper flakes.
Mix these dry and aromatic ingredients together thoroughly—this distributes all the seasonings evenly.
Gently fold in the cooked spinach and diced chicken until just combined, being careful not to overwork the mixture.
I like to use my hands for this final mixing so I can feel when everything is evenly distributed without compacting the filling too much.
Step 4: Stuff and Season the Mushrooms
- 1/4 teaspoon salt
- 1/4 teaspoon black pepper
- chicken and spinach filling from Step 3
- Cooking spray
Lower the oven temperature to 425°F.
Arrange the roasted mushroom caps gill-side down on the baking sheet (this orientation keeps them stable and allows the filling to stay in place).
Season the tops of the mushrooms lightly with the remaining 1/4 teaspoon salt and 1/4 teaspoon black pepper.
Divide the filling mixture evenly among the six mushroom caps, mounding it slightly on top of each one.
Flatten the tops gently with the back of a spoon so the filling sits securely, then lightly spray the filling with cooking spray to help it brown during baking.
Step 5: Bake Until Chicken is Cooked Through
- 6 oz mozzarella
Bake the stuffed mushrooms at 425°F for 15-20 minutes, until the filling is heated through and the chicken is nearly cooked.
Use a meat thermometer to check the internal temperature of the filling—aim for about 160°F at this stage.
Remove the mushrooms from the oven, top each one with shredded or sliced mozzarella cheese, then return to the oven for another 3-5 minutes, just until the cheese melts and the filling reaches 165°F internally.
I always check the chicken temperature with a thermometer because the filling can look done before it actually is, especially when it's stuffed inside the mushroom.
Step 6: Heat Sauce and Plate
- 2 cups marinara sauce
- 2 tablespoons fresh parsley
While the mushrooms are in the final stage of baking, warm the marinara sauce in a small saucepan over medium heat, stirring occasionally to ensure even heating (about 5 minutes).
Once the mushrooms are fully cooked and the cheese is melted, transfer them carefully to a serving platter or individual plates.
Pour the warm marinara sauce evenly over each stuffed mushroom, then top with an extra light sprinkle of shredded mozzarella if desired, and garnish with the fresh parsley.
Serve immediately while everything is hot.
Mouthwatering Chicken and Spinach Stuffed Portobello Mushrooms
Ingredients
For the mushrooms:
- 6 large portobello mushroom caps (stems and gills removed)
- 1/4 teaspoon salt
- 1/4 teaspoon black pepper
For the filling:
- 1 lb chicken (finely diced into 1/4-inch pieces)
- 10 oz spinach (wilted, squeezed very dry, and chopped)
- 1/2 cup parmesan cheese (Sartori Classic preferred)
- 1 small onion (finely minced)
- 1 egg (lightly beaten)
- 8 cloves garlic (minced)
- 1/3 cup fresh parsley (chopped)
- 3/4 tsp onion powder
- 1 tsp salt
- 1 tsp pepper
- 1/2 tsp dried oregano
- 1/4 tsp red pepper flakes
For the topping and sauce:
- 2 cups marinara sauce (such as Rao’s Homemade)
- 6 oz mozzarella (shredded or sliced for extra melt)
- 2 tablespoons fresh parsley (for garnish)
Instructions
- Start by wilting the spinach in a large skillet over medium heat, stirring occasionally until completely wilted (about 3-4 minutes). Transfer to a fine-mesh strainer or colander and squeeze very firmly with your hands or the back of a spoon to remove as much liquid as possible—this is crucial for preventing a watery filling. Chop the squeezed spinach finely and set aside. While the spinach cools slightly, mince the garlic and onion as finely as possible, chop the fresh parsley, and dice the chicken into small, uniform 1/4-inch pieces. Having everything prepped before you start cooking ensures the filling comes together quickly.
- Preheat your oven to 450°F and line a large baking sheet with parchment paper. Clean the portobello mushroom caps with a damp cloth and use a small spoon to gently scrape out and remove the dark gills from the underside—this prevents the mushrooms from releasing too much moisture during cooking. Remove the stems as well. Place the mushroom caps gill-side up on the prepared baking sheet, then roast for 10 minutes. After 10 minutes, carefully flip them over (gill-side down) and roast for another 5 minutes. This initial roasting helps render some of the mushroom's moisture and sets the caps.
- Remove the mushrooms from the oven and carefully pour out any accumulated liquid from the pan. In a medium bowl, combine the parmesan cheese, chopped parsley, minced onion, lightly beaten egg, minced garlic, onion powder, salt, pepper, dried oregano, and red pepper flakes. Mix these dry and aromatic ingredients together thoroughly—this distributes all the seasonings evenly. Gently fold in the cooked spinach and diced chicken until just combined, being careful not to overwork the mixture. I like to use my hands for this final mixing so I can feel when everything is evenly distributed without compacting the filling too much.
- Lower the oven temperature to 425°F. Arrange the roasted mushroom caps gill-side down on the baking sheet (this orientation keeps them stable and allows the filling to stay in place). Season the tops of the mushrooms lightly with the remaining 1/4 teaspoon salt and 1/4 teaspoon black pepper. Divide the filling mixture evenly among the six mushroom caps, mounding it slightly on top of each one. Flatten the tops gently with the back of a spoon so the filling sits securely, then lightly spray the filling with cooking spray to help it brown during baking.
- Bake the stuffed mushrooms at 425°F for 15-20 minutes, until the filling is heated through and the chicken is nearly cooked. Use a meat thermometer to check the internal temperature of the filling—aim for about 160°F at this stage. Remove the mushrooms from the oven, top each one with shredded or sliced mozzarella cheese, then return to the oven for another 3-5 minutes, just until the cheese melts and the filling reaches 165°F internally. I always check the chicken temperature with a thermometer because the filling can look done before it actually is, especially when it's stuffed inside the mushroom.
- While the mushrooms are in the final stage of baking, warm the marinara sauce in a small saucepan over medium heat, stirring occasionally to ensure even heating (about 5 minutes). Once the mushrooms are fully cooked and the cheese is melted, transfer them carefully to a serving platter or individual plates. Pour the warm marinara sauce evenly over each stuffed mushroom, then top with an extra light sprinkle of shredded mozzarella if desired, and garnish with the fresh parsley. Serve immediately while everything is hot.
