Combine chile peppers, lime juice, and garlic in a bowl. Add 1/4 cup orange juice and molasses; stir until marinade is combined.
Shred the prickly pears in a food processor; mix into marinade.
Place chicken legs, chicken thighs, potatoes, turnips, and mushrooms in a baking pan; pour in marinade and remaining orange juice. Refrigerate until flavors combine, 1 to 8 hours.
Preheat oven to 375 degrees F (190 degrees C).
Bake chicken in preheated oven until no longer pink at the bone and the juices run clear, about 1 hour. An instant-read thermometer inserted into the thickest part of the thigh, near the bone should read 165 degrees F (74 degrees C).