Heat oil in a casserole dish over medium high heat. Add beef and brown meat on all sides. Reduce heat, add onion and cook until soft but not browned. Add onion soup mix, wine, water and salsa. Bring to boil.
Cover and place in preheated oven for 2 1/2 to 3 hours. Check occasionally to make sure there is sufficient liquid in bottom of pan; add more wine if necessary. Before serving shred beef.