Prep the vegetables: Peel and dice the sweet potato into ½-inch cubes. Dice the zucchini, onion, and bell pepper. Mince the garlic.
Brown the beef: Heat a large skillet over medium-high heat. Add oil if needed, then cook the ground beef for 5–7 minutes until browned. Drain excess grease.
Cook the aromatics: Add onion and bell pepper to the skillet. Cook for 3–4 minutes until softened, then add garlic and cook for 30 seconds.
Soften the sweet potatoes: Add sweet potatoes, broth or water, and a pinch of salt. Cover and cook for 5–8 minutes, stirring occasionally, until almost tender.
Add the zucchini: Stir in the zucchini and cook uncovered for 3–5 minutes, until tender but not mushy.
Add sauce and seasonings: Stir in tomato sauce, smoked paprika, oregano, black pepper, and crushed red pepper if using. Cook for 1–2 minutes until everything is well coated.
Finish and serve: Top with fresh parsley or cilantro. Add cheese if desired, cover for 2 minutes to melt, then serve warm.
