You need to learn a recipe based on fish (ingredients only mean fish, not a certain kind of fish, such as sushi), then take all the fish out of the refrigerator, only put clown fish, and then click the button to make sushi (not just this recipe). If the sushi button doesn't show 5 simulated coins, it should be no problem.

It's better for a cook to have no fish on him, otherwise he may cook with the fish on him.

Really? Sushi also has some fish? Didn't you just say fish (didn't you choose dike fish when purchasing ingredients according to sushi recipes? That is automatically selected by the system, because any fish system will automatically help you choose the cheapest fish.

You can look up all the recipes and see if there are any fish.