A method for cooking a ham (5) comprises the following steps:-inserting the ham (5) to be cooked into a casing (1) made of plastics for foodstuffs；- sealing the casing (1) by welding on the casing (1) a closing sheet (7) made of plastics for foodstuffs；- creating a vacuum inside said casing (1) during said welding；- inserting the casing (1) with inside the ham (5) into a cooking device in which the ham is cooked,- before said sealing, inside the casing (1) an elastic pressure device (6； 14； 30) is inserted, such that after sealing of the casing (1), said elastic pressure device (6； 14； 30) is interposed between the ham (5) and said closing sheet (7), said expansion device (6； 14； 30) being so configured as to define internally a space (S； S') in which liquids (8) can collect that exit the ham (5) during cooking.An elastic pressure device, (6； 14； 30), configured for being used during cooking of a ham (5) by inserting the device inside a casing (1) containing the ham (5) to be cooked, comprises a first plate (9； 15) and a second plate (11； 16) and at least one elastic element (12； 17) fixed to at least one of said first plate (9； 15) and said second plate (11； 16), said at least one elastic element (12； 17) maintaining the first plate (9； 15) and the second plate (11； 16) spaced apart from one another, so that a space (S； S') is defined therebetween.
