Here’s a method for cold-smoking precooked shrimp. It will add flavor, but the shrimp should be refrigerated after smoking and should be eaten within a week. For best results, you’ll need a large pot that won’t crowd the shrimp during boiling. Add some salt—about 1 cup per gallon. Remove the heads of the shrimp and devein them, but leave the tails on. Bring the water to a boil, add the shrimp, bring back to a boil, and cook for 3 minutes for medium shrimp. (Large shrimp require another minute; smaller shrimp, less time. The shrimp are ready when they turn pink.) Drain the shrimp and arrange them on racks. Cold-smoke for 30 to 60 minutes, depending on size. Eat the smoked shrimp cold, or put them into shrimp salad or other dishes. I like a few chopped shrimp scrambled with chicken eggs and a spring onion or two chopped with half the green tops.