Beef with tortillas

2 teaspoons olive oil 2 cups thinly sliced fennel 1 cup thinly sliced onion 1/2 teaspoon salt, divided 1/2 teaspoon freshly ground black pepper, divided 1/8[...]

1 1/2 pound beef, flank steak 1 each onion sliced 1 each green bell pepper cut into strips 1 each sweet red bell pepper cut into strips 1 each jalapeño pepper[...]