This beautiful method of cooking delicate fish is perfect for entertaining. The packets make a gorgeous presentation.

• Prepare and preheat grill. In a small skillet, heat oil over medium heat. Add onion and garlic; cook and stir until tender, about 6 to 7 minutes. Remove from heat and stir in wine, salt, and pepper.

• Return to high heat and boil until reduced by half, about 5 minutes. Remove from heat and stir in tarragon. Set aside.

• Tear off four 12″ × 18″ pieces of heavy duty foil and place on work surface. Divide spinach into quarters and place on foil. Cut fish into four pieces and place on top of spinach. Spoon onion mixture on fish and top with green bell pepper strips.

• Bring up long edges of foil and, leaving some space for steam expansion, seal with a double fold, then fold in short ends to seal. Place on grill rack 6 inches from medium coals. Grill, turning packets twice and rearranging on grill, until fish flakes easily when tested with fork, about 15 to 20 minutes. Serve immediately.

En papillote

Food cooked in foil or parchment paper is called en papillote. This method of cooking keeps food moist and is an excellent way to cook delicate foods like greens and fish. The food steams in the packet, sealing in juices and flavor. Warn your guests to be careful opening these packets because steam will billow out.