Preheat a large skillet over medium-high heat.

Wash and chop the bell peppers, onion, and zucchini into thin slices.

In a small bowl, mix together cumin, smoked paprika, chili powder, garlic powder, and salt.

Add olive oil to the preheated skillet, then add the sliced vegetables and spice mix to the skillet.

Stir occasionally, cooking for about 10-12 minutes or until the vegetables are tender.

While the vegetables are cooking, warm the corn tortillas in a separate skillet or in the oven.

Once the vegetables are cooked, squeeze lime juice over them and stir in the fresh cilantro leaves.

Serve the vegetable mixture on warm tortillas and top with desired toppings.