With a blender to realize a cream with the sugar, the juice of lemon, the garlic, the ginger, the coriander, the seeds of cumin and mustard, the curcuma and the salt. In alternative to the blender to use a mortar uniting subsequently the juice of lemon. To take a frying pan with the heavy fund and to heat 1 spoon of oil. To add the onion and to cook for 4 minutes. The onion has to become transparent. To unite the spices and, mixing, to cook for 3 minutes. To extinguish the fire and to put back. Before washing and to dry the frog to turn on the grill. To cut the fillets, realizing some pieces of about 5 centimeters of width. To mix the mixture of the frying pan in a bowl, to add the yogurt and to mix. To put back half the mixture in a sauce-boat. To dress again the frog with the other half, placing it repeatedly in the bread crumb. After having submitted the whole fish to this operation to move to a heat-resistant pan. To pour the remainder oil on the fish. To cook on the grill to a distance of 7,5 centimeters. To heat the oven to 230° C. and to insert the heat-resistant pan cooking for 10 minutes. It has to become very hard to the touch. With a spatula to extract from the heat-resistant pan, to deposit in the dish and to serve it together with the sauce to the yogurt.