Halibut with Grapefruit, Parsley, Red Onion, and Shiitake Mushrooms

Slice the top and bottom of grapefruits with a paring knife. Set one of the flat sides on your work surface. From top to bottom, following the curve of the fruit, cut away peel and white pith. Trim off any remaining pith. Holding the grapefruit over a medium bowl, cut along both sides of 12 segments, staying close to the membrane, to release; discard any seeds.

Squeeze juice from remaining sections into a small bowl, discarding any seeds. You should have about 1/2 cup juice.

Add parsley, onion, and olive oil to bowl with grapefruit sections; season with salt and pepper and gently toss to combine. Cover and set aside.

Pour grapefruit juice into a small nonreactive saucepan and bring to a boil over high heat. Continue boiling juice until reduced to a thick glaze, about 5 minutes. Whisk in cream and let reduce for 1 minute. Remove saucepan from heat and whisk in 1/2 cup butter, one piece at a time. Whisk in hot sauce and season with salt and pepper; cover and set aside.

Heat 1/4 cup of grapeseed oil in a large skillet over medium heat. Add mushrooms and cook, stirring, until beginning to crisp, about 4 minutes. Season with salt and pepper; set aside, covered, to keep warm.

Heat remaining 1/4 cup grapeseed oil in a medium skillet over medium-high heat. Season halibut fillets with salt and pepper and place them in skillet. Add remaining tablespoon butter and let melt to prevent fish from sticking to pan. Cook fish, turning once, until opaque, about 3 minutes per side.

Divide mushrooms evenly between 4 serving plates. Top each with grapefruit salad and a halibut fillet. Spoon over sauce and serve immediately.