1. Zest and juice orange, lemon and lime. Add oil, grated onion, finely grated garlic, rosemary, salt and pepper.
2. Butterfly chicken legs: make a parallel cut down the leg in the center, touching the bone. Then make two more cuts on each side of the chicken leg bone. Push the meat flat.
3. Add chicken pieces to the marinade, toss to coat and marinate in the fridge for at least 30 minutes.
4. Preheat oven to 400F (200C).
5. Transfer chicken pieces to a baking sheet and cook for 45-50 minutes.
6. Meanwhile, prepare the sauce. To a hand blender bowl, add lime juice, avocado oil, mayo, seeded jalapeño, parsley, garlic, season with salt and pepper. Blend with an immersion blender until smooth.
7. Drizzle chicken pieces with the sauce and enjoy!