Mahi Mahi with Tropical Sauce

2 fillets mahi mahi
1/2 tablespoon olive or coconut oil
1 1/4 tablespoons sweet onion diced
1 tablespoon fresh ginger diced
1/2 cup pineapple juice
3 tablespoons orange juice
7 tablespoons light coconut milk
1 tablespoon reduced-sodium soy sauce
1 tablespoon rice vinegar
1 teaspoon fish sauce
1/8 teaspoon pure stevia or 1 tablespoon liquid sweetener of choice: agave, honey, etc.
A pinch of salt
1 tablespoon cornstarch
Water

If toasting macadamia nuts, preheat your oven to 350°F. Spread the nuts on a cooking sheet and pop them in there until just lightly browned, around 6 or 7 minutes.
Preheat your grill to high.
While the grill is preheating, dice the sweet onions and ginger.
Add the oil to a medium-sized pan and preheat over medium heat.
Add the sweet onions and ginger and cook until soft, about 5 minutes.
Place your fish on the grill. It will take around 5-7 minutes per side, depending on how thick your fillet is. Only flip it once.
While your fish is grilling, add the pineapple juice, orange juice, coconut milk, soy sauce, rice vinegar, fish sauce, sweetener, and pinch of salt to the pan. Stir until it just all combines.
Mix the cornstarch with 1 tablespoon water and 1 tablespoon of the sauce from the pan and add it into the mix.
Stir, and bring to a boil.
Turn down the heat to medium low and let it simmer until nice and thick, about 5 minutes.
Transfer your fish to plates and spoon sauce over each fillet. Garnish with the macadamia nuts, and green onion and cilantro if you'd like.