Make a paste of turmeric, 1 tablespoon mustard oil, and salt. Apply the mixture to the shrimp. Cover and refrigerate for at least an hour.
Heat the remaining oil in a medium-sized saute pan over medium heat and saute the marinated shrimp for 3 minutes. Remove from heat and keep aside.
Heat the vegetable oil in a large skillet over medium heat. Add mustard seeds, cloves, cinnamon stick, and bay leaf. Cook, stirring constantly until it is toasted and fragrant (for about 2 minutes). Add chopped onions and cook till it is translucent (for about 2 minutes). Add cayenne pepper and 1/2 cup water and cook until the oil separates (for about 5 minutes).
Lower the heat and add the coconut milk and the sauteed shrimp. Simmer until the shrimp are cooked (for about 4 minutes).
Transfer to a serving dish and garnish with fresh coriander leaves and eat it with Basmati Rice.