Since you’re already firing up the grill to cook the fish, have a little fun and take advantage of that fire by first grilling a pepper, some tomatillos, and a thick slice of onion so that you can whip up a flavorful salsa before putting your fish on the grate.
Tomatillos look like tough, green tomatoes. They have a similar composition of skin on the outside, seeds on the inside. They come wrapped in a waxy, leafy exterior that needs to be removed before you cook with them. They have a naturally acidic flavors and balance out really nicely with Mexican peppers.
This dinner comes together very quickly and is a great meal to mix into your weeknight menus.

Grilled Halibut with Tomatillo Salsa
1 Tbs. extra-virgin olive oil; more as needed
4 large tomatillos, husked, rinsed, and dried
1 medium poblano or anaheim chile, split in half lengthwise, stemmed, and seeded
1 thick slice from a large yellow onion
1 Tbs. fresh lime juice; more to taste
1/2 tsp. minced garlic
1/4 tsp. cayenne
2 Tbs. coarsely chopped fresh cilantro
Kosher salt and freshly ground black pepper
4 6-oz. skinless halibut fillets extra-virgin olive oil, for grilling
Kosher salt and freshly ground black pepper
Fresh lime juice (optional)
Lime or lemon wedges, for serving
Red radishes, thinly sliced, for garnish
Cilantro leaves, for garnish
Prepare a medium (350°F to 375°F) charcoal grill fire. Using a long-handled spatula, push the coals to the center of the grill; or light the center burner on a gas grill and heat to medium. When the grill is hot, oil the grill grate. Grill the tomatillos, turning, until browned and softened, about 12 minutes. Grill the pepper until blistered and charred, about 13 minutes. Grill the onion until charred on both sides, 10 to 15 minutes.
Transfer the vegetables to a work surface. Remove the skin from the pepper, and coarsely chop the vegetables. Scoop the vegetables into a medium bowl, and add the 1 Tbs. of oil, lime juice, garlic, and cayenne. Let the salsa cool to room temperature, and then stir in the cilantro. Season to taste with salt, pepper, and lime juice.
Lightly brush the halibut on both sides with oil, and season with salt, pepper, and lime juice, if you like. Oil the grill grate, and grill the halibut until just cooked through, with the grill covered and the vents open, turning once, until a digital meat thermometer inserted into the thickest part of the fish reads 125°F, about 8 minutes total, depending on the heat of the grill and the thickness of the fish.
With a fish spatula, transfer the halibut to individual plates and serve with the salsa, lime or lemon wedges, radishes, and cilantro.