Preheat oven to 400 degrees with a rack in the center.
In a small bowl, stir honey, soy sauce, lemon juice, and mustard.
Place salmon fillets skin side down on a foil lined baking sheet.
Pour glaze over salmon.
Bake until fish is opaque but still pink inside (around 15-20 minutes). Baste every few minutes with glaze from the pan.
Serve with Roasted Root Vegetables.