Preheat broiler on high (if applicable), with racks in the upper and lower thirds.
Line the bottom of a baking tray with parchment paper, place the flour tortillas, and wrap foil tightly across the top. Set in the lower third of your oven.
On a separate baking tray, add sliced peppers and onions, drizzle with avocado oil, and toss together. Then sprinkle with salt, pepper (if using), and chili powder, arrange in a single layer, and put the tray in the top third of your oven to broil, uncovered, for 8 minutes. Flip over after 4 minutes. Vegetables should be softened and slightly charred.
After 8 minutes, take out the vegetable tray, and slide vegetables to the sides of the tray. Then put the steak slices in the middle, drizzle with remaining avocado oil, and toss. Sprinkle with salt and chili powder, to taste. Arrange in a single layer, and put the tray back in the top third of the oven to broil, uncovered, for 8 minutes. Flip over after 4 minutes. The steak will be tender and just slightly charred.
Remove the tortillas and vegetable/steak tray from the oven when fully cooked. Let stand for 5 minutes and then dig in! Serve with the fixings that your family loves.