In a small bowl, mix together the mustard, lemon juice, honey, olive oil, soy sauce, ginger, garlic, paprika, salt, and red pepper flakes and mix until combined.
Place the trout into a large dish and pour the marinade over the fish. Place into the refrigerator for 1 hour or up to 4 hours.
Preheat the oven to 425 degrees and place a couple of pieces of aluminium foil onto a baking sheet, slightly overlapping.
Place the trout filet onto the foil and crinkle the edges to form a boat. Pour the leftover marinade over the fish evenly.
Bake on the center rack for 18-24 minutes or until internal temperature reaches 145 degrees and flakes easily with a fork.
You can turn your oven to broil on high the last 5 minutes to brown the top more if you prefer.
Remove from the oven and drizzle the melted butter over the salmon and a drizzle or two of honey, and serve with extra lemon slices!
Notes
Salmon could also be used if you prefer.Store leftover fish in the fridge in an airtight container for 2 to 3 days.