To be honest, we didn't spend much time visiting the village. We were there for the Abbey, and otherwise passing through on our way to Limoux.
There's more than one restaurant in Saint Hilaire village. The signs for Le Clos Saint-Hilaire Hotel Restaurant looked rather classy.
We ate lunch at the Restaurant de l'Abbaye, directly across the street from the Abbey entrance. It's a typical French café-restaurant, with good but basic home-cooked meals. We went for the menu bulot, which translates to "working-man's lunch". The quality was fabulous, but the quantity was over the top: we struggled to match the appetite of a working man.
Restaurant de l'Abbaye café has a lounge area with arm chairs and sofa, classical French style of leather and wood of course.