In a skillet, sauté onion and garlic until soft, then transfer to the crockpot.
Add minced meat and brown lightly before adding to the crockpot.
Stir in grated carrot, zucchini, tomatoes, tomato paste, oregano, basil, salt, and pepper.
Cover and cook on low for 6–7 hours or high for 3–4 hours.
Cook spaghetti according to package directions just before serving.
Serve spaghetti topped with the sauce, garnished with basil and parmesan.