Heat the avocado oil in a large skillet over medium-high heat. Add the sweet potato cubes and cook for 4–5 minutes, stirring occasionally until they begin to soften.
Stir in the zucchini, red bell pepper, onion, and garlic. Cook for another 3–4 minutes until the vegetables are slightly tender.
Push the vegetables to one side of the skillet. Add the ground beef to the empty side and cook for 7–9 minutes, breaking it into small crumbles as it browns. Drain excess grease if necessary.
Reduce the heat to medium-low. Add the black beans, fire-roasted tomatoes with their juices, frozen corn, and taco seasoning. Stir everything together until evenly combined. This Ground Beef and Zucchini Skillet comes together beautifully as the vegetables soak up the savory taco seasoning.
Sprinkle the shredded cheese evenly over the top. Cover the skillet, remove it from the heat, and let the cheese melt for about 2 minutes.
Garnish with cilantro, green onions, avocado, sour cream, or a squeeze of fresh lime juice before serving.