Step 1Use a meat mallet, rolling pin or heavy skillet to gently tap each shrimp 3 or 4 times to crush lightly. Season the shrimp with salt. Beat the eggs and yolks with the fish sauce.
Step 2Combine the oil and annatto in a small nonstick skillet. Set over medium-low heat and stir until the oil turns deep orange, 3 to 4 minutes. Add the garlic and sizzle, stirring, until fragrant, about 45 seconds. Add the shrimp and cook, stirring, until just opaque throughout and curled, about 2 minutes. Pour in the egg mixture and cook, stirring, until just set, 1 to 2 minutes. Serve immediately.