Lebanese tuna casserole  (Servings: 8     Prep time: 25 Minutes) Ingredients 2 cans tuna medium 2 onions (big) thinly sliced 1 cup water 1/2 cup vegetable oil 1/4 cup 7 Spice or white pepper White vinegar for tuna marinade The Tahini Sauce  1/2 cup Tahini 2 cloves garlic pounded to creamy texture 1 cup water as…