In a bowl, mix the ground chicken, egg, chopped onion, chicken fond, salt and pepper.
Knead mixture together with hand till evenly combined. Form mixture into balls.
In large non-stick skillet, warm butter over high heat.
Place meatballs in pan and cook until all sides are browned and cooked throughout.
Slowly stir in heavy cream and creme fraiche. Add fond, fresh thyme and bring to a simmer until sauce starts to thicken. Salt and pepper to taste.
Serve with mashed cauliflower and sugar free lingonberry jam.