Put the yogurt, onion, garlic, cilantro, lemon juice, curry powder, cumin, salt and pepper in a medium bowl or a large jar with a lid.
Whisk or shake to combine well.
Notes
Yogurt in Marinades
This yogurt based marinade is great on lamb, chicken, and salmon, in particular. The yogurt acts as a tenderizer for the meat, and provides a rich, cooling counterpoint to the rich spices. It also adds richness; I am a fan of greek yogurt in marinades, and I almost always go for fuller fat than not. You can choose between nonfat, 1 or % or a whole milk yogurt which can reach up to 10%, and is lovely and full flavored.