Shrimp are ready to eat when they turn bright pink and the flesh is opaque. Small shrimp will cook in as little as 2 minutes, medium shrimp take about 4 minutes and large shrimp will cook in 5-6 minutes. This recipe calls for raw shrimp, which are a gray color. If your shrimp are already pink, you may have purchased pre-cooked shrimp. If this is the case, you'll want to just warm them briefly so that they don't get tough.