A quick note on grouper: it's over-fished and over-farmed. So please make sure you're using sustainable fish. A good place to check is this handy guide from the Monterey Bay Aquarium.
4 Grouper Fillets 1” thick
6 Tbsp. butter plus more for bread
1 Baguette (Dutch Crunch works best)
2 Tbsp. paprika
4 tsp. kosher salt
2 tsp. EACH of garlic powder and onion powder
1/8 tsp. cayenne pepper
1/2 tsp. EACH of red pepper flakes and cumin
1/2 tsp. black pepper
1 tsp. EACH of dried oregano and thyme
1 sweet onion, chopped
4 cups mushrooms, sliced
8 slices of jack cheese
1. Heat grill. Place spices in a bowl and mix well. Divide baguette into four sections the length of a fillet and then split each in half.
2. Melt 2 Tbsp butter in a frying pan on medium-high heat. Saute onion until soft and translucent. Add mushrooms and cook until soft and golden. Set aside.
3. Melt remaining butter and turn off heat. Place fillet in pan just long enough to coat with butter. Remove fillets and set aside. Do the same with the inside face of the baguettes. Liberally sprinkle the spice mixture on all sides of fish to coat.
4. Grill fish 3-4 min. on each side until fish flakes easily. Grill bread until just golden. Place fillet on one side of bread and top with onions, mushrooms and cheese. You can choose to broil at this point.
Place tarter sauce on baguette and enjoy!