1/4 cup olive oil, plus more as needed
3 tablespoons roughly chopped fresh cilantro
1 teaspoon ground cumin
3 chipotle chiles in adobo
2 cloves garlic, roughly chopped
Juice of 2 limes, plus more as needed
Juice of 1 orange
Salt and freshly ground black pepper
2 1/4 pounds skirt steak, trimmed
2 red bell peppers, thinly sliced
1 large onion, thinly sliced
12 flour tortillas
Combine the olive oil, cilantro, cumin, chipotles, garlic, lime juice, orange juice and 1 teaspoon salt in a 2-cup measuring cup or similar vessel. Using an immersion blender, puree the marinade until smooth. Transfer to a resealable plastic bag. Add the steak to the bag, then seal and shake to coat. Refrigerate for 2 to 4 hours.
Preheat a ridged grill pan over medium-high heat (or prepare an outdoor grill).
Drain the marinade from the steak and sprinkle liberally with salt and pepper. Lightly oil the grill pan. Grill the steak for 4 minutes per side for medium-rare. (Depending on the size of your grill pan, you may need to cook in batches.) Transfer to a cutting board to rest.
Toss the bell peppers and onions with some olive oil and lime juice. Grill the vegetables until barely limp, 7 to 8 minutes.
Turn any free burners to a medium-low flame. Place a tortilla on each flame and let char for 30 seconds to 1 minute. Flip and repeat on the second side. Wrap the tortillas in a clean tea towel to keep warm while you continue with the remaining tortillas.
Thinly slice the steak on a diagonal, against the grain. Serve with the warm tortillas and grilled vegetables.