To BOIL a lobster tail: Completely thaw lobster tail in the refrigerator. In a large kettle, bring enough water to a boil to cover lobster tails; add 1 tbsp. salt, if desired, for each quart of water. Place thawed tails in boiling water. When water returns to a boil, reduce heat and simmer (do not boil), covered, 5 min. for a 4 oz. tail. Add 1 min. for each additional ounce. Remove from pot. Plunge into an ice bath to stop the cooking; drain.
TO BROIL or BAKE a lobster tail: Cut lobster tail lengthwise through center of hard top shell with kitchen scissors; cut through meat with sharp knife without cutting through soft undershell. Spread open; place on broiler pan. Brush with melted butter; sprinkle with salt. Broil 4-6” from heat or bake in a preheated 350° oven until meat is firm (10-15 min., depending on size).
CLARIFIED (DRAWN) BUTTER: In a small saucepan over low heat, slowly melt desired amount of butter. Remove from heat and let stand until the clear part can be spooned off into a serving dish (2-3 min.); discard milky solids. Serve warm.