Butterflying

Butterflying is the way of preparing meat, fish, or poultry for cooking by cutting it almost in two, but leaving the two parts connected; it is for then often boned together with flattened. Spatchcocking is a particular method for butterflying poultry that involves removing the backbone, & spatchcock as a noun may refer to a bird prepared in that way.

Other

Butterflying shrimp or lobster tail involves cutting the tough top side, without cutting all the way down to the other, softer side.