Step 2
Cut a few shallow slits into each chicken drumstick, and place into a resealable plastic bag; set aside. Heat 5 tablespoons of vegetable oil in a Dutch oven or large pot over medium-high heat. Stir in the onion, garlic, and ginger. Cook and stir until the onion has turned golden brown, about 7 minutes. Remove the pot from the heat, and use a slotted spoon to scoop the onion mixture into a blender. Leave as much oil in the pot as you can, and set aside. Add 3 tablespoons white vinegar, coriander, cumin, garam masala, black pepper, salt, turmeric, and cayenne pepper. Puree until smooth, then pour into the bag with the chicken; mix until the chicken is evenly coated, and squeeze out excess air. Marinate at room temperature for 1 hour, or in the refrigerator for 3 hours or longer.