In a large bowl, whisk together the adobo sauce, vegetable oil, cumin, garlic powder, onion powder, salt and pepper. Add the mushrooms, peppers and onions, gently tossing to coat.
Spread the peppers and onions in a single layer on a sheet pan. On another sheet pan, arrange the mushrooms and onions in a single layer.
Roast the vegetables for 20-25 minutes until browned and caramelized at the edges. About halfway through cooking, toss the peppers and flip the mushrooms and onions. Serve with tortillas, cilantro and salsa.