Step 5
Heat a large, deep skillet over medium-low heat. Add olive oil, yellow squash, zucchini, bell pepper, onion, Italian seasoning, basil, black pepper, oregano, garlic powder, thyme, and red pepper flakes. Cook and stir until vegetables are tender, about 10 minutes. Pour in tomato sauce and simmer until heated through, adding the beef halfway through, about 10 minutes more.