Thaw the frozen collard greens if not already done, then place them in a clean kitchen towel and squeeze out as much excess moisture as possible—this prevents a watery dip. While squeezing, heat the olive oil in a small skillet over medium heat. Add the minced shallot and garlic, stirring frequently for 2-3 minutes until fragrant and softened but not browned. The aromatics will infuse the oil with flavor that carries through the entire dip.

In a large bowl, combine the mayonnaise, sour cream, flour, salt, black pepper, and hot sauce. Stir in the prepared collard greens from Step 1 along with the cooked shallot and garlic mixture. Add the Rotel tomatoes with their juices and fold in 6 oz of the shredded Monterey Jack cheese (reserving 2 oz for topping). The flour acts as a thickener and helps prevent the dip from becoming too wet during baking. I find this approach keeps the texture creamy rather than soupy.

Transfer the dip mixture to a 9x13 inch baking dish or similar size casserole, spreading it into an even layer. Top with the reserved 2 oz Monterey Jack cheese, then sprinkle the freshly grated Parmesan cheese evenly over the top. The dual cheese topping will create a golden, flavorful crust while the Parmesan adds a nutty depth.

Bake at 350°F for 25-30 minutes until the dip is heated through and bubbling at the edges. For a more golden, browned top, turn on the broiler for the last 2-3 minutes, watching closely so the cheese doesn't burn. I like to broil just until the top is lightly browned and crispy—this adds a wonderful textural contrast to the creamy dip.