What type of butter is used on the steamed vegetables?

The correct choice is lemon pepper butter, as it enhances the flavor profile of the steamed vegetables by adding a zesty and aromatic twist. This type of butter combines traditional butter with lemon and spices, creating a vibrant addition that complements the natural flavors of the vegetables. It not only adds richness but also a citrusy brightness that elevates the dish.

Regular salted butter, while commonly used in various culinary applications, does not provide the distinct flavor enhancement that lemon pepper butter does in this specific context. Butter flavored margarine, similar to regular butter, lacks the unique elements of lemon and spices, which are essential for delivering that desired taste experience. Olive oil, though a popular choice for sautéing or drizzling, does not deliver the same creamy texture or flavor profile associated with butter, specifically in this context of pairing with steamed vegetables.