Chop celery, carrots, onion and garlic.
Salt and pepper roast, then in large skillet heat olive oil, sear roast on all sides, put into slow cooker.
If no oil is left in frying pan add 2 more tbsp of olive oil or butter, then add flour to skillet and cook until browned. Using a whisk deglaze with some of the red wine, then add tomato paste to skillet , after scraping all the good brown bits from pan add remaining wine, beer, worcestershire sauce and beef broth. Whisk to ensure no lumps. (if you do get lumps pour broth through strainer to remove).
Put onions, garlic, celery, carrots, thyme and bay leaves on top of roast
Pour broth over roast and vegetables. Cover and cook until tender appx. 5 hours on high 8 hours on low.
If necessary thicken gravy to desired consistency. Transfer broth to cooking pot (make a slurry- 1 tbsp flour to ¼ cup flour shake well in a jar). Heat broth on stove top to boiling, gradually adding flour mix while whisking, add a bit at a time to get desired consistency. Reduce heat and cook for a few more minutes to thicken.