Microwave: Wrap in barely damp paper towels and microwave on high for 30 to 45 seconds.
Oven: Wrap in foil and bake at 300ºF until steaming, about 5 minutes.
Steamer: Wrap a stack of 12 tortillas in a clean, heavy towel, place in a steamer over 1/2 inch of water, cover and bring to a boil over medium-high heat. When steam is released, time 1 minute, then remove from the heat and let stand 15 to 20 minutes. Held in a very low oven, the tortillas will stay warm and moist for an hour or more.
Microwave: Wrap in barely damp paper towels and microwave on high for 30 to 45 seconds.
Oven: Wrap in foil and bake at 300ºF until steaming, about 5 minutes.
Steamer: Wrap a stack of 12 tortillas in a clean, heavy towel, place in a steamer over 1/2 inch of water, cover and bring to a boil over medium-high heat. When steam is released, time 1 minute, then remove from the heat and let stand 15 to 20 minutes. Held in a very low oven, the tortillas will stay warm and moist for an hour or more.
Links:
[1] http://www.eatingwell.com/recipes/poblano_skirt_steak_fajitas.html