Friends since they met at The Times in the mid-1990s, the two talk in the shorthand of an old married couple. In the amount of time it takes to finish a cocktail, they will have discussed Hill politics, office politics and sex, and made two references to Nora Ephron, to whom the book is dedicated.

The idea came from Mr. Bruni, 52; meatloaf is the only dish he has complete confidence cooking. He had long nursed a fantasy that one day he would add a meatloaf cookbook to his literary oeuvre, which includes books about President George W. Bush, college admission anxiety and his own struggle with weight.

Ms. Steinhauer, 48, who occasionally writes about food for The Times and the food blog Food52, just came off a good run with the snack cookbook “Treat Yourself,” which had taken her to QVC and the “Today” show. She was casting around for the next one. Mr. Bruni offered his meatloaf idea. She talked him into doing it together.

“At some point we thought, ‘Isn’t this a moment for meatloaf?’” Ms. Steinhauer said. “‘Can we make meatloaf ecumenical?’”

The book’s first recipe is essentially the Chevy of meatloaves, built from ground beef seasoned with onions and topped with tomato sauce. It’s from Mr. Bruni’s mother, Leslie Bruni.

The authors call it a populist meatloaf, but soon the recipes that follow take a pluralist turn. Dry Spanish chorizo and manchego cheese marry inside a loaf of ground pork. Chopped ahi tuna is covered with a clove-scented sauce of mushrooms, tomatoes and red wine. There are loaves infused with the flavors of Japan and China. Lamb, their favorite meat to make into a loaf, is punctuated with mint, pine nuts, couscous and harissa.