Drain sweet potato; put in bowl of food processor.
Prep the onion; set aside.
Heat the oil in a skillet. Add the onion, lower the heat and let cook slowly for about 20 minutes or until the onion is very soft and translucent. Add minced garlic in final 5 minutes of cooking.
Add the onion mixture to the food processor, along with the yoghurt, the lemon juice and chili powder process until smooth.
Adjust taste with salt sub and pepper.
Chill until you are ready to serve it. Will keep in fridge in covered container for up to 5 days.
Notes
Optional: put a few drops of hot sauce in it, or, sprinkle a few drops of hot sauce on it when serving.Serve with crackers, naan, and / or cut up fresh vegetables such as celery, carrots, broccoli, cauliflower, mushrooms etc.You can use regular no-fat yoghurt, but it might taste "thin" without the mouthfeel that Greek yoghurt can give. You could also try a low-fat ricotta, or cottage cheese.