In a 6-quart enameled cast iron Dutch oven, saute the bacon in the olive oil over medium heat. Once lightly browned, remove with a slotted spoon and set aside.
Pat the beef dry with paper towels, as it will not brown properly if wet.
Let the bacon fat and oil heat up until very hot, almost smoking. Saute a few pieces of beef at a time in the hot oil and bacon fat until they are evenly browned.
Remove the beef from the pot and set aside on a plate or sheet pan lined with parchment paper. Season with salt and pepper to taste.
Brown the onion and carrots in the fat. Drain the cooking fat. Preheat the oven to 325 degrees F.
Dissolve beef base in very hot water. Stir with a spoon to dissolve. Set aside.
Return the beef and bacon to the Dutch oven.
Sprinkle with the beef with flour and stir with a wooden spoon to evenly coat. Cook for about 5 minutes over medium-high heat, stirring occasionally. Lightly brown the flour.
Stir in the wine and beef stock so the meat is just barely covered. Add the tomato paste, garlic, parsley, and thyme. Bring to a simmer then cover.
Place the pot in the middle of the oven for 2 ½ to 3 hours, until the meat is tender.
In a skillet over medium heat, melt the butter. Once the butter is hot and foamy cook add the mushrooms and cook until browned. Stir occasionally to coat them with butter as the cook.
During the last 30 minutes of cooking, remove the lid, place the pearl onions and mushrooms over the top of the stew, and put the lid back on.
Remove the pot from the oven and skim off any excess fat. Serve over mashed potatoes, boiled potatoes, or cooked rice.