When cooking boiled fish, how many minutes should the fillets be cooked? Why do fish fillets break so easily? Fish fillets can be taken out after being boiled in boiling water for about 40-60 seconds, and can't exceed 90 seconds at most. It is easier to break if cooked for too long. In addition, it is also important to master the heat. If the heat is too high, the fillets will be boiled and the taste will be affected. Add starch and stir for 1 min. Only after this step, the fillets will not be broken. ?