beef (flank or sirloin), sliced into strips — 450 g (1 lb)
small bell peppers, sliced — 2
large onion, sliced — 1/2
olive oil — 3 tablespoons
chili powder — 1/2 tablespoon
black pepper — 1/4 teaspoon
ground cumin — 1.5 teaspoon
salt — 1 teaspoon
paprika — 1 teaspoon
garlic powder — 1 teaspoon
dried sriracha (optional) — 1/2 teaspoon
Small tortillas (for serving)
Sour cream (to taste, for serving)
Avocado (to taste, for serving)