You will need to find a Greek or Mid-Eastern market to get taramosalata, which is a dip-like paste of carp roe. That being said, I've made a substitute version that's easier to find: take a jar of caviar off-the-shelf at the supermarket (buy the best - most expensive - one they have). Mix it with sour cream or yogurt. Voila! You've done it!
This time I "cured" whole shrimp (10 oz. 21-25's for 2 servings) instead of slicing them in half. Drop peeled shrimp into boiling water. After 30 seconds drain and rinse under cold water. Steep in a mixture of lemon juice (1 lemon), lime juice (2 limes), shallot, and salt for 30 minutes (in the fridge). If you're not going to eat the shrimp immediately drain off the juice to stop the "cooking" and keep them refrigerated.
Toss in a mix of taramosalata and sour cream (proportions are up to you - I go about 1 to 1) or the substitute I suggested above. It's a delicious protein for a hot summer's supper.