Mix the marinade: kefir, paprika, garlic, lemon juice and zest.
Put the chicken thighs in a plastic freezer bag and pour over the marinade. Marinate in the fridge for up to 12 hours - minimum 30 minutes.
When you are ready to cook, preheat your grill/ BBQ / oven to medium high heat.
Remove your chicken from the marinade and place directly onto the grill. or in a baking tray. ( If baked, pour over the marinade).
Cook for 20 minutes or so on the grill/BBQ , flipping them regularly, until the chicken is cooked through. In the oven it should take 35-40 minutes to cook through.
Serve warm or at room temperature.