Blend the marinade

• Add the orange juice, pineapple juice, lime juice, olive oil and apple cider vinegar to a blender.
• Add the salt, pepper, garlic powder, onion powder, Mexican oregano, comino, paprika, cloves and achiote powder.
• Blend into a fine, smooth consistency.

Marinate the steak

• Pour the marinade over the skirt steaks in a bowl and turn to coat well.
• Cover and marinate overnight in the refrigerator.

Grill the fajitas

• Heat the grill until very hot.
• Grill the steaks with the whole jalapeños alongside, flipping a couple of times, until cooked to your liking.

Slice and assemble

• Slice the steak across the grain.
• Spread guacamole on a flour tortilla, add the steak and top with cilantro, onion and a squeeze of lime.