In a large pot, cook the pasta in boiling water according to package directions. Drain the pasta and set aside.
Heat olive oil and butter in a large, deep skillet. Add onions, red pepper, and mushrooms, and cook until soft. Remove to a plate.
Add the garlic and red pepper flakes and cook until fragrant.
Add the shrimp, sun-dried tomatoes, lemon zest and salt and pepper to taste. Cook until the shrimp start to turn pink. Add Italian seasoning, fresh basil, and spinach and cook until the spinach is wilted.
Add the pasta to the pot with the parmesan and lemon juice. Stir to combine.
Plate the pasta and sprinkle with additional fresh parmesan.