Matsutake mushrooms, considered by the Japanese to be the finest of all mushroom varieties, add fresh flavor to this broiled bass recipe from Michael Cimarusti, head executive chef at Providence.Also try:Striped Bass with Yuzu Kosho and Wilted Spinach
Heat 1 tablespoon olive oil and 1 tablespoon butter in a medium high-sided skillet over medium-high heat. Add 8 ounces mushrooms and cook, stirring, until lightly browned, 1 to 2 minutes. Season with salt and espelette pepper. Add sake to deglaze, scraping up any browned bits from bottom of skillet; cook until sake is reduced by half.
Add chicken stock and 1/8 teaspoon lemon juice; season with salt and espelette pepper. Add rosemary sprigs and let cook until liquid is reduced by half. Using a slotted spoon remove mushrooms and rosemary; set mushrooms aside and discard rosemary.
Gradually add remaining 1/4 cup (1/2 stick) butter and 1 tablespoon olive oil to skillet, using an immersion blender to combine. Add mushrooms and stir to coat. Set mushrooms aside in a warm place.
Preheat broiler; lightly oil a small baking sheet and set aside. Heat remaining 2 tablespoons olive oil in a large nonstick ovenproof pan over high heat. Season on both sides with salt and pepper. Add fish to skillet, skin side down. Cook until skin is crisp, 4 to 5 minutes. Transfer to prepared baking sheet and place under broiler; cook until fish is no longer opaque, about 1 minute more. Remove from broiler and keep warm.
Add chopped rosemary and stir into mushroom mixture along with chives; divide mushroom mixture evenly among 4 plates. Top each with a fish fillet and thinly sliced mushrooms; season with salt and pepper. Spoon any remaining sauce from mushroom mixture around fish; serve immediately.