In a large dutch oven, drizzle with olive oil and add bacon. Allow bacon to cook and render its fat for about 5 minutes. Once done, remove to a plate and set aside.
Dredge cubed beef in flour so that all sides of the meat are covered.Sear the meat in the bacon fat on all sides. Its ok not to cook the meat all the way, that will be done later. When done, remove meat to another plate and set aside.
*You may have to do this in 2 batches so don't overcrowd pot.
In the same pot, add onion, carrots, celery, garlic and fresh oregano. Season with salt and pepper. Saute until vegetables begin to soften, about 5 minutes.
Add red wine and deglaze pan. Bring it to a high boil then using a wooden spoon, scraping all of the bits on the bottom. The wine should reduce by half. Add tomato paste and stir through.
Add mushrooms, potato, bacon, bay leaves and 4 cups of stock. Bring to a high simmer and then reduce to a slow simmer. Place cover on and allow to cook for about 3 hours,or until meat and potatoes are tender.