This is another one of those recipes where you aren't going to get precise measurements, but a general guideline and the reassurance that you really can't screw this up. Trust me. It's also super easy and one that's incredibly versatile.
Preheat oven to 375
On your sheet pan, lay out all of your Onion Slices, Pepper Slices & Mushrooms. Season with Salt, Pepper & Garlic. Drizzle Olive Oil over the top.
Toss your Meat with Taco Seasoning and let it set for about 10 minutes to absorb the flavor. If you're using a really lean protein, add a bit of oil & toss well. We normally use Chicken, but I've also used Beef, Pork & Shrimp. You can certainly leave the meat out if you choose.
Spread meat over veggies and place into oven. Bake 35-45 minutes until veggies are tender. I stir it all together about 1/2 way through the baking time.
Serve in hot tortillas (Flour, Corn, Spinach, Gluten-Free) with toppings of your choice.