While sandwiches in Europe may be on a crisp baguette, chewy pretzel or a dense multigrain roll, the fillings also vary by region and sometimes adapt the name of their hometown, such as Neufchâte cheese and Parma ham. Even a global giant like Chicago-based McDonald’s Corp. recognizes the need to cater to local tastes with sandwiches such as Spain’s Grand McExtreme Bacon Burger, which was featured on its International Favorites menu this summer. Or how about the McVegan in Sweden where 1 in 10 people describe themselves as vegan or vegetarian?

“If McDonald’s has to show variation, you need to adjust to regionality all throughout Europe,” said Thomas Eisele, chief executive officer for food service, Valora Management, a Muttenz, Switzerland-based firm that owns Brezelbӓckerie Ditsch, a global supplier of traditional and German-style pretzels.

Eating occasions also vary by country. Take the classic croissant.

“In France, it’s mainly a breakfast item whereas in The Netherlands, it is mainly considered as bread,” said Filip Eeckhout, marketing manager, Vandemoortele, a Ghent, Belgium-based supplier of frozen baked goods, including pre-proofed, frozen dough croissants. “As long as it’s plain, the Dutch will cut it and put cheese in it for a sandwich. In Italy, it’s served mainly for breakfast with a cappuccino.”

Vandemoortele also produces multiple formats of focaccia at its Genoa, Italy, bakery.

“In Italy, it’s sold like pizza. You say you want one piece, and they cut it by weight before you,” Mr. Eeckhout explained. “In the rest of Europe, people put some ham, cheese or vegetables in between it as a sandwich.”