• 8 1 1/2-2“-thick lamb loin chops (about 3 pounds)
• 2/3 cup sorrel or spinach leaves
• 1/3 cup mint leaves
• 1/3 cup parsley leaves
• 1 tablespoon finely grated lemon zest
• 5 garlic cloves, thinly sliced, divided
• 4 ounces king oyster or maitake mushrooms, cut into 1/2″ pieces
• 1 shallot, thinly sliced
• 1 bunch mustard greens, ribs and stems removed, leaves torn into pieces
• 1 teaspoon crushed red pepper flakes
• 1/3 cup plus 2 tablespoons olive oil
• 1 tablespoon fresh lemon juice (add up to 3 tablespoons total if using spinach)
• Kosher salt, freshly ground pepper
• 1 tablespoon white balsamic vinegar

Pat lamb dry; season with salt and pepper. Let sit at room temperature 1 hour. Meanwhile, purée sorrel, mint, parsley, lemon zest, red pepper flakes, about 1 garlic clove, and ⅓ C. oil in a blender, scraping down sides as needed, until mixture is smooth. Season salsa verde with salt and pepper; set aside. Prepare grill for high heat (or heat a grill pan over high). Grill chops, turning every 2 minutes or so, until well browned and beginning to char and a thermometer inserted into the thickest part registers 125°, 8–10 minutes. Let lamb rest at least 10 minutes. While lamb is resting, heat remaining 2 T. oil in a large skillet over medium-high. Cook mushrooms, tossing occasionally, until well browned, about 4 minutes. Transfer to a large plate. Reduce heat to medium and add shallot and remaining garlic to skillet. Cook, stirring occasionally, until shallot is softened and starting to brown, about 2 minutes. Add greens; season with salt and pepper. Cook, stirring occasionally, until wilted and bright green, about 2 minutes. Return mushrooms to skillet and toss to combine. Stir in vinegar; season with salt and pepper. Stir lemon juice into salsa verde; taste and adjust seasoning with salt and pepper. Serve lamb chops over mustard greens with salsa verde. Do Ahead: Salsa verde (without lemon juice) can be made 1 day ahead. Cover and chill. Add lemon juice before serving.