Add all seasonings to a large, sealable bag and shake to combine.
Pour in orange juice and lime juice and shake gently to combine.
Place skirt steak into baggie, shake, and place in fridge for 4+ hours. Turn bag over a couple times while marinating.
Add 2 tablespoons of oil to a cast iron skillet and heat over medium high heat.
Add vegetables and cook until tender, but still crisp. Remove from pan. Set aside.
Add remaining oil to pan and heat over medium high heat.
Remove steak from baggie and place in cast iron skillet. Discard marinade.
Cook the meat on medium high for 4-6 minutes per side.
Remove from skillet and place on a cutting board. Cut steak into thin strips, against the grain.
Place onions, peppers, and steak back into the pan, stir to combine then serve on flour tortillas.