Fill a saucepot with 1-inch of water. Place mussels in pot, cover, and steam until mussels open, discarding any that do not open. Remove mussels from pan and chill.
In a mixing bowl, combine cucumber, tomatoes
, onion, garlic, tomato paste
, hot sauce
juice and season with salt and pepper. When mussels
are cold, split the shells, leaving the mussel on the half-shell and discarding the other half. Spoon some of the mixture on top of mussel. Garnish
with sour cream, if desired.