Mix soy sauce, maple syrup, garlic, ginger, pepper, and salt in a small bowl.
Place salmon in a small container and seal. Marinate in the refrigerator for 30 minutes.
Preheat the grill for high heat and lightly oil the grate. Once heated, turn down one side to low heat.
Place salmon, skin-side down, over low heat on the preheated grill and close the lid.
Cook for about 20 minutes .
Serve the salmon with tomatoes, asparagus and lemon aside.