In a large skillet heat oil over high heat. Sear each tuna steak on each side, about 2 to 3 minutes per side. In a large baking dish layer onions and tuna.
In a small bowl, mix together the remaining 9 ingredients (salt and pepper through stevia) except for the spinach.
Pour the sauce over the tuna and vegetables and place baking dish in the oven. Bake for 10 to 15 minutes, until onions are slightly tender and tuna has a thick strip of pink in the center.
Serve tuna and onions over a bed of spinach.
Notes
SERVING SUGGESTION: Cauli-rice (process cauliflower in a blender or food processor until it resembles grains of rice; steam “rice” till tender; drain; salt and pepper to taste then fluff with a fork).GLUTEN FREE: Make sure soy sauce is gluten free.NUTRITION: 467 Calories; 29g Fat (55.8% calories from fat); 42g Protein; 9g Carbohydrate; 2g Dietary Fiber; 65mg Cholesterol; 695mg Sodium. Exchanges: 0 Grain (Starch); 5 1/2 Lean Meat; 1 ½ Vegetable; 0 Fruit; 4 Fat.