Heat up cast iron skillet, melt ½ of butter in hot pan. Add mushrooms to cover bottom of pan. Cook mushrooms for about 5-7 minutes, or until soft and crispy. Cook remaining mushrooms in butter. Set aside.
Add sausage links and garlic to pan. Cook until seared on 2 sides. Remove and slice. Add back mushrooms, and then spinach and cooked tortellini to skillet. Stir together. Add lemon juice. Remove from heat, add sliced tomatoes, parmesan cheese, and salt and pepper. Enjoy