Sir Paul McCartney has revealed how his perfect sandwich comes together; a marmite, hummus and honey mustard bagel.

The rock legend led comedian Romesh Ranganathan through the steps to make the snack during a conversation about new cookbook Linda McCartney’s Family Kitchen.

“I do a very good sandwich,” he said.

“I take a bagel, I cut it in three.”

“Often you have two bagels, so now you cut it into six. So you’ve got a top and a bottom, a top and a bottom, and two middles.

“You can get three sandwiches out of that.”

The Beatles singer then explained the mechanics of the bagel – adding protective structural layers.

“So the bottom layer I put Marmite on and then I would put a little bit of lettuce, because I’m going to put hummus on but it’s going to go through the hole if I don’t put lettuce on,” he said.

“You might get a little sliced cheese on there, you might have one slice of tomato, then you might have a pickle or two.

“Then you go back to your lettuce barrier, because there’s another hole on the top remember, so you’ve got to protect it from that.

“Then I put on honey mustard.”

His daughter Mary McCartney added: “In a McCartney sandwich we are not afraid of a condiment.”

Linda McCartney’s Family Kitchen is available now.