How you say mustard greens in Spanish?

The most common way to say "mustard greens" in Spanish is "berza".

However, it's important to note that "berza" is a broader term that refers to various types of leafy green vegetables, including collard greens and kale. To be more specific, you can say:

* "Mostaza" (mustard) + "verdes" (greens) = "Mostaza verdes"

* "Mostaza" (mustard) + "hojas" (leaves) = "Hojas de mostaza"

Both of these phrases accurately describe the specific type of leafy green vegetable you're referring to.