Pre-heat oven to 350 degrees.
In a large bowl, mix the grated onion, ground turkey, almond flour, fennel greens, fennel bulb, egg, lemon juice and zest, mint, garlic, salt and pepper with hands. Add any extra almond flour if needed to make thick enough to form into meat balls.
Form into about 1 inch meatballs and place on an oiled baking sheet or in a large baking dish.
Place in the oven for approximately 30-40 minutes or until cooked through.
While baking, mix the ingredients for the sauce and prepare salad of choice.
Serve meatballs with the yogurt sauce and salad on the side. The yogurt dip also makes a great salad dressing.