Marinate skirt steak by brushing with olive oil and sprinkling with 1 teaspoon paprika and oregano per side, 1/2 teaspoon cumin per side, salt and pepper - let sit for at least one hour before grilling to marinate. Cut peppers into quarters and clean seeds, trim scallions.
Make Pico de Gallo by combining all ingredients in a bowl and set aside until ready to serve.
Heat grill on high heat for 10 minutes. Put meat, peppers and spring onions on grill and then turn to medium heat. Cook veggies until charred and soft, remove to a warm platter. Cook steak for about 8-10 minutes per side and then turn and cook another 8-10 minutes, until desired doneness. Let meat rest before slicing into thin slices against grain.
Place tortillas on grill or stove top and char slightly, wrap in towel to keep warm. Slice peppers and arrange on platter with onions and meat.
To serve - fill tortilla with desired ingredients and toppings and enjoy. Serves 4-6.