Preheat the oven to 400 degrees F. (see notes)
Whisk the soy sauce, honey, mustard, ginger and Sriracha together in a small bowl.
Heat the oil in a large oven-safe sauté pan over medium high heat. When the pan is hot, place the salmon fillets in the pan, skin side up. Cook 2-3 minutes without moving, until a golden crust forms. Turn the fillets over and transfer the pan to the oven. Cook 5-6 minutes or until salmon is almost cooked through but still just slightly pink in the middle. Carefully remove the pan from the oven and transfer the salmon to a platter.
Pour off any drippings from the pan, and heat the pan on the stove over medium high heat. Add the soy sauce mixture to the pan and cook 2-3 minutes until slightly thickened. Pour the glaze over the salmon. Garnish with scallions if desired.