Preheat the grill or oven to medium-high heat.
In a small bowl, whisk together the Dijon mustard, honey, lemon juice, olive oil, salt, and pepper.
Brush the fish steaks with the Dijon mustard mixture, coating both sides.
Grill the fish steaks for about 5 to 7 minutes per side, or until cooked through and the fish flakes easily with a fork. If using the oven, bake for about 12 to 15 minutes, or until cooked through.
Serve the fish steaks with the remaining Dijon mustard sauce on the side.
Enjoy!