Saute onion in hot oil until tender. Dredge venison in flour & brown in oil. Add salt, thyme, bay leaf, pepper, bouillon, & wine; cook at a simmer for one hour, stirring occasionally. If necessary, add more wine or bouillon. Saute mushrooms in butter; add meat & simmer for about 30 minutes more or until meat is tender.
Serve with potatoes or over rice or noodles.