Use oven-safe bowls or small dishes. Pan spray, shove tortillas in, and bake at 375 °F until they start to brown (guessing 10-12 minutes, but honestly use my nose). Easy, and cuts out all the fat of restaurants that fry their taco salad bowls.
You can briefly (10 sec) microwave tortillas to make more pliable before forming in dish.
For a crispier bowl, pan spray the tortilla after putting in bowl. Don't use too much or it will be too greasy.
Select any safe flour tortilla for this. If using corn tortillas, look for the largest ones you can find.
Corn Substitutions: Corn is a common ingredient in products. Starch, modified food starch, dextrin and maltodextrin can be from corn. Consult with your physician to find out which corn derivatives you need to avoid. Many corn-free options are available in the US. Find out more about corn substitutions.
Gluten: Gluten is a protein found in specific grains (wheat, spelt, kamut, barley, rye). Other grains are naturally gluten-free but may have cross-contact with gluten-containing grains. Look for certified gluten-free products if you need to avoid gluten. Find out more about wheat and gluten substitutions.