Hot serrano chiles, sweet Meyer lemons, and refreshing parsley and mint come together for a flavor-packed relish that’s also full of antioxidants and polyphenols.
Halve lemon lengthwise. Juice 1 half into a small bowl. Slice remaining half lengthwise into 2 wedges; trim ends, and remove and discard seeds. Cut each wedge crosswise into thin (about 1/8-inch-thick) slices. Add lemon slices to juice in bowl; gently stir in parsley, mint, shallot, chile, garlic, vinegar, 4 1/2 tablespoons oil, and 1/4 teaspoon salt.
Pat salmon dry with paper towels. Heat remaining 1 tablespoon oil in a large nonstick skillet over medium-high until oil is shimmering and fragrant. Add salmon, skin side down. Press down gently on flesh with a spatula until skin stays flat in skillet; sprinkle evenly with 1/4 teaspoon salt. Cook, undisturbed, until skin is crispy and brown around edges, about 8 minutes. Flip salmon, and sprinkle evenly with remaining 1/4 teaspoon salt. Cook until desired degree of doneness, about 2 minutes for medium. Transfer salmon to plates; spoon lemon relish evenly over salmon.