Pre-heat oven to 350 degrees. Pre-heat a dutch oven over medium heat. Add olive oil. Add chicken, salt, pepper and oregano. Cook chicken for 4-5 minutes stirring often until browned and no longer pink on the outside.
Add mushrooms, onion and garlic. Cook an additional 3-4 minutes or until mushrooms are softened. Add marsala, sherry and lemon juice. Cook until almost evaporated. Stir in cream of chicken soup and water.
Remove pan from heat and stir in frozen tortellini. In a medium bowl, combine 1 cup of the Sargento® Reserve Series™ Aged Italian Blend Cheese, 1/2 cup of the Sargento® Reserve Series™ 18-Month Aged Cheddar Cheese and 2 tablespoons of flour. Add to the pan. Reserve remaining cheese for sprinkling on top after it has baked. Transfer mixture to a greased 13” X 9” Baking dish. Cover with foil. Place dish in oven.
Bake for 45 minutes. Remove foil and stir in parsley and grape tomatoes. Sprinkle with remaining cheese. Bake uncovered an additional 10 minutes or until cheese is melted. Let casserole rest for 10 minutes before serving. Garnish with additional chopped parsley if desired.
Note: This casserole reheats really well. Just spoon leftovers into a bowl and microwave on high until heated through.
For added nutrition and flavor, feel free to add vegetables such as broccoli, asparagus, tomatoes or chopped brussels sprouts before baking.