Peel the shrimp and toss with salt.
Combine coriander, cumin, fennel, mint, garlic, Cayenne pepper, and yogurt in a bowl.
Mix with the shrimp and let marinate for 1 hour.

Dip:
Grate the cucumber and squeeze it through a sieve to extract as much juice as possible.
Mix the grated cucumber with yogurt, lemon juice, mint, and coriander seeds.
Season with salt. Set aside.

Preheat the grill to medium temperature.
Remove the shrimp from the marinade, drain, and brush with oil.
Grill the shrimp for about 2 minutes per side, or until they are pink and curled.
Let cool.

Take 12 appetizer spoons.
Divide the dip among the spoons, then place 2 or 3 shrimp on each spoon.
Ready to serve.