The phrase "a broad foundation" is correct and usable in written English.
You can use it when discussing a strong base or starting point for further development, whether in education, business, or other contexts.
Example: "The new curriculum provides a broad foundation in mathematics that will benefit students in their future studies."
Alternatives: "a solid base" or "a wide base of knowledge".
The house macaroni and cheese is ideally shared, unless you're laying a broad foundation for an evening of drink.
This paper presents a broad foundation for a full-featured biomechanical simulator for the human musculoskeletal system physiology.
The undergraduate minor in Humanities provides Stanford students with a broad foundation in the humanities, emphasizing literature, philosophy, and history.
The success of these projects has been supported by a broad foundation of engineering science in superconductor development, electrical and cryogenic engineering.
The undergraduate program leading to the Bachelor of Science in Theater Arts degree comprises a broad foundation in theoretical and practical studies, and intensive performance and design practica.
Most of the early writings on birds are more anecdotal than scientific, but they represent a broad foundation of knowledge, including much folklore, on which later work was based.
A broader foundation for the divinity of the king is the view of the king as the son of a god, which can take on different forms.
Dentistry students, for example, spend the first two years of their studies with the students of medicine, giving them a broader foundation and, eventually, a Doctor of Dental Medicine degree rather than the Doctor of Dental Surgery degree that is more common in Western schools.
Today, having been through the famous bust, and now booming once again on a broader foundation that includes high tech and health care as well as energy, the nation's fourth-largest city is a more mature and in many ways a much more diverse and interesting place.
