Haven't made this yet, but I had to share because it looks sooooo good. In Advance: Beef Bourguignonne's flavor improves with time. Make it 1 or 2 days ahead of time, then cover and refrigerate it, keeping the onions and mushrooms separate from the stew. The next day, skim any fat from the surface. Reheat the stew over a medium-low flame for 45 minutes.