In a large cast iron skillet, heat 2 tablespoons of extra-virgin olive oil over medium-high heat. Sauté 1 cup of sliced Bella mushrooms until golden brown, about 4-5 minutes. Add 1 cup of halved cherry tomatoes and cook for an additional 2 minutes. Stir in 3 cloves of minced garlic and 5 cups of baby spinach until wilted.

Sprinkle in kosher salt, freshly ground black pepper, and 1/4 teaspoon of red pepper flakes to taste. Stir the mixture thoroughly and let the flavors meld together.

Lower the heat and stir in 1 cup of ricotta cheese along with 1/2 cup of chicken broth, mixing well until creamy. Cook for about 2-3 minutes until it begins to bubble. Add 1/2 cup of freshly grated Parmesan cheese, stirring until melted.

In a separate non-stick skillet, melt 2 tablespoons of unsalted butter over medium-high heat. Add lemon slices, then place 4 fish fillets in the skillet. Cook each side for 3-4 minutes until flaky.

To serve, place a scoop of the creamy spinach mixture on each plate, top with flaky fish fillets, and finish with a squeeze of fresh lemon juice.