Eric Ripert's Red Snapper and Morels in Port Reduction

Bring Port to a boil in a small heavy saucepan over medium-high heat. Lower heat and simmer until reduced by half (if using a gas stove, make sure flames don’t lick the side of the pan; if they do, the Port will burn and the sauce will be bitter). Add vinegar and simmer, lowering heat as needed to keep liquid from burning around the edges, until reduced to an almost syrupy consistency, 8–10 minutes. Remove from heat.

Preheat oven to 250°. Season snapper on both sides with salt and pepper. Sprinkle five-spice powder over skin and rub it in. Heat 1 Tbsp. oil in a large nonstick skillet over high until just smoking. Add 2 snapper fillets to skillet, skin side down, and press down gently on fillets with a spatula to prevent skin from shrinking. Cook until skin is darkened and crisp, about 5 minutes. Turn and cook until fish is just barely cooked through, about 5 minutes longer. You can check by inserting a paring knife or metal skewer into thickest part of flesh; it should slide easily through fillet and come out warm after 5 seconds. Transfer fish to a rimmed baking sheet and place in oven to keep warm. Wipe out skillet and repeat process with another 1 Tbsp. oil and remaining 2 fillets.

Heat 1 Tbsp. oil in a large skillet over high until just smoking. Add half of asparagus, reduce heat to medium, and cook, turning occasionally, until browned, about 3 minutes. Add half of mushrooms and cook, tossing occasionally, until tender, about 4 minutes; season with salt and pepper. Transfer vegetables to a plate.

Wipe out skillet and repeat process with remaining asparagus, mushrooms, and 1 Tbsp. oil. Return all vegetables to skillet and add thyme and 2 Tbsp. butter. Cook, tossing, until butter is melted and coats vegetables, about 2 minutes.

Bring Port reduction to a boil in a small saucepan over high heat. Cut remaining 3 Tbsp. butter into small pieces. Remove pan from heat and gradually add butter, swirling reduction in pan until emulsified, about 3 minutes. It should look shiny, not greasy.

Toss chives into vegetables. Serve vegetables topped with fish with Port sauce spooned around.

Do Ahead: Sauce can be made 1 week ahead. Let cool; cover and chill.