In a medium saucepan, whisk together all the sauce ingredients. Heat over medium heat, stirring occasionally, for 10 minutes while mixture cooks.
In a large skillet, heat the raw coconut oil or ghee and sauté the onion over medium-low heat until translucent, about 5 minutes. Add the black garlic, ground turkey or alternative, rosemary, sea salt, and pepper. Cook, stirring, for 8 to 10 minutes, until the turkey is cooked through. Add beans and cauliflower and cook for 2 more minutes.
In a small bowl, stir together the yogurt and lemon juice.
Spoon 2 tablespoons of the filling into each lettuce cup and top with 1 tablespoon of the sauce and optional Greek yogurt topping. Garnish with the topping, if desired, and serve.