Thick halibut fillets are ideal for grilling. Their firm texture will maintain shape without flaking apart on the grill, and their mild flavor is enhanced by the char and smoke. While you can simply grill the fillets whole, try cutting the fish into large chunks and threading the pieces on skewers. The smaller pieces will expose more edges and corners to the fire, which increases charring and the coveted crispy bits.
In this recipe, a quick marinade adds more flavor to the mild halibut. A key ingredient in the marinade is coarsely grated onion. The onion pulp and juice contribute sweetness and sharpness, nicely acting as a tenderizer and balancing the salt and acidity. Alternate the pieces of fish with sweet peppers and red onion on the skewers. The grilled vegetables will infuse more flavor into the fish and provide appealing color to the skewers. (Adding vegetables is also a great way to stretch pricey fish to feed a crowd.)
