Why do we use à to describe French foods?
…other examples I can think of include tarte aux fraises, omelette du fromage.. why don’t we use avec here?
The general rule is that we use the French preposition à to delineate an ingredient in a recipe.
The nuance is subtle, but you could also appreciate it in English. Look at the following comparison below:
Yaourt aux fraises = strawberry yogurt
By using this, we understand that strawberries are adequately incorporated into the yogurt and they change the flavor profile completely.
Yaourt avec des fraises = yogurt with strawberries
By using this phrase, it’s implied that you’re eating yogurt with a side of strawberries. The yogurt is likely plain in nature without the strawberries being a defining feature of the yogurt.
If we look at another example, gâteau au chocolat translates beautifully into English as chocolate cake. Chocolate is merely an ingredient of the cake, but it’s incorporation changes everything from the color of the cake to the main flavor.
However exceptions do exist to using the preposition à with ingredients.
For example, the correct French word for cherry jam would be confiture de cerises. This is because without the cherries, there would be no jam. Unlike our chocolate cake example, you would and could still have a cake without the chocolate.
A small point, omelette du fromage is not correct French. This erroneous French phrase stems from a children’s cartoon known as Dexter’s Laboratory. The correct term for an “egg and cheese omelette” in French is omelette au fromage. This follows the general rule outlined in the first section.
I hope this helps answer your question about when we primarily use the French preposition à when talking about foods.