Using a sheel pata or a heavy rolling pin, very slightly pound the shrimps all over. Make sure that the skin or shell does not break off.
Mix the shrimps with the ginger, garlic, onion and green chilli slices. Mix in the lemon extract, mustard oil, salt and coriander leaves.
Heat a thick tawa (use two tawas on top of each other if they a thick tawa is not available), and while the tawa gets heated, wrap all of the shrimps in an aluminum foil. Place the shrimps in wrapped foil on the heated tawa.
Heat on the tawa for 15-25 minutes.
Unfold the foil paper and serve the baked shrimp on lettuce leaves. You can also garnish with some green chillies.