- 1 pound broccolini or broccoli rabe, trimmed
- Kosher salt
- 2 tablespoons unsalted butter
- 1 teaspoon finely grated lemon zest
- 1/2 teaspoon crushed red pepper flakes
- Freshly ground black pepper
- 4 (6-ounce) black bass or trout fillets or skinless cod or haddock fillets
- 1 cup all-purpose flour
- Kosher salt, freshly ground pepper
- 6 tablespoons unsalted butter, room temperature, divided Maître d'Hôtel Butter , Nasturtium Butter , and Chile-Cilantro Butter
- Cook broccolini in a pot of boiling salted water just until tender, about 3 minutes. Drain and transfer to a bowl of ice water; let cool. Drain and pat dry with paper towels.
- Heat butter in a medium skillet over medium until foaming. Add broccolini, lemon zest, and red pepper flakes; season with salt and pepper. Cook, tossing, just until broccolini is warmed through and coated in butter.
- Heat a grill pan over medium-high until hot but not smoking. Pat black bass fillets dry; this will help keep the fish from sticking to the pan while cooking. Place flour on a plate and season generously with salt and pepper (you are not seasoning the fish itself). Working one at a time, dredge fillets in flour, shaking off excess. Spread butter over flesh side of fillets as if buttering a slice of bread.
- Add fillets, flesh side down, to pan; they should sizzle upon contact. Cook just until grill marks appear and butter is browned, about 1 minute. Turn and cook, pressing gently so entire skin side is in contact with the pan's ridges, until skin is browned and crisp and fillets are cooked through, about 4 minutes longer.
- Serve black bass fillets with broccolini and flavored butters, which will soften on contact with the warm fish.