Preheat your grill to medium-high heat (around 400°F). If using a grill pan, heat it over medium-high heat.
In a small bowl, mix chili powder, cumin, garlic powder, salt, and pepper with olive oil to create your seasoning mixture.
Brush the vegetables with the seasoning mixture, making sure they're evenly coated.
Place vegetables on the hot grill. Cook for 4-5 minutes per side, or until they develop nice grill marks and are tender but still slightly crisp.
While the vegetables are grilling, wrap your tortillas in foil and place them on the cooler side of the grill to warm through.
Once grilled, slice the vegetables into bite-sized pieces.
Assemble your tacos by filling each warm tortilla with grilled vegetables, fresh cilantro, and your choice of toppings.
Serve immediately with lime wedges on the side.