In a large bowl, add yogurt, red onion, garlic, cumin, dried basil, salt and pepper. Whisk well.
Add chicken thighs and using tongs toss gently to coat chicken in marinade. Cover bowl with plastic wrap and marinate in the fridge anywhere from 1 hour up to 24 hours.
Preheat grill on medium-high (450-500 degrees F) and rub with oiled paper towel. Brush big pieces of red onion and some marinade from the chicken and place on the grill. Close the lid and grill chicken thighs for 10-12 minutes or chicken breasts for 8-10 minutes turning once. Do not overcook.
Remove chicken from the grill, cover with foil and let rest for 5 minutes. Serve with a side of grain and salad, use in salads or perfect for a meal prep.
Notes
Store: Refrigerate cooked chicken leftovers in an airtight container for up to 5 days or freeze for up to 3 months.
Freeze marinated chicken: Marinate in a Ziploc container, let out air and lay flat in the freezer. No need to marinate in the fridge first. When ready to cook, thaw in the fridge overnight and cook as per recipe.