Preheat your oven to 375°F (190°C) and lightly grease an 8 x 11-inch casserole dish. Line a baking sheet with parchment paper. Cut the gold potatoes into small cubes, then place them on the lined baking sheet. Drizzle the potatoes with olive oil and toss to coat evenly. Spread the cubes in a single layer and roast in the oven for 20 minutes, flipping them halfway through for even cooking.

While the potatoes are roasting, dice the boneless chicken breasts into bite-sized pieces and place them in a large mixing bowl. Season the chicken with fine sea salt and ground black pepper. Chop the broccoli into small florets and finely mince the garlic cloves. Add both the broccoli and garlic to the bowl with the chicken.

Once the potatoes are finished roasting, add them to the bowl with the chicken, broccoli, and garlic. Stir gently to combine. Next, add the sour cream and mayonnaise. Mix thoroughly to coat all the ingredients evenly. I like to take a moment and taste the mixture at this stage for seasoning; you can adjust the salt or pepper to your liking before baking.

Transfer the combined mixture into the prepared casserole dish and spread it out evenly. Sprinkle shredded cheese evenly over the top to ensure a gooey, golden crust after baking.

Bake the casserole in the preheated oven for 45 to 50 minutes, or until the top is golden and bubbling and the chicken is fully cooked through. Remove the casserole from the oven and let it rest for 5 minutes before serving. Letting it rest helps the flavors meld and the casserole set slightly, making it easier to serve. For a fresh finish, sometimes I garnish with a handful of chopped fresh herbs, if available.