Note To make liquid chicken fat, place 1kg chicken fat with a small amount of water in a saucepan over low heat for a few hours until fat has rendered out. Strain through a fine sieve. Makes around 300 ml. The collars are the two triangular pieces with side fins attached left after filleting between head and body. Chicken glaze is heavily reduced homemade chicken stock, or you can use melted butter for brushing.