3 pounds cubed beef stew meat
1/4 cup all-purpose flour
1/2 teaspoon salt
3 tablespoons olive oil
3 tablespoons Worcestershire sauce
1 pound carrots, peeled and cut into 2-inch pieces
4 large potatoes, cubed
1 tablespoon dried parsley
1 1/2 teaspoons ground black pepper
2 cups boiling water
2 (1 ounce) envelopes onion soup mix
3 tablespoons butter
3 large onions, quartered
2 tablespoons minced garlic
1/2 cup burgundy wine
2 (6 ounce) packages fresh button mushrooms, halved
1/4 cup warm water
3 tablespoons cornstarch
Toss the beef, flour, and salt in a sealable bag until the beef is coated.
Heat the oil in a large skillet over medium-high heat. Combine the beef and Worcestershire sauce in the skillet; cook until the beef is evenly browned on all sides; transfer to a slow cooker, but do not clean the skillet. Add the carrots, potatoes, parsley, and pepper to the slow cooker.
Combine the boiling water and soup mix in a small bowl; add to slow cooker.
Melt the butter in the skillet over medium-high heat. Cook the onion and garlic in the melted butter until soft; transfer the onion and garlic to the slow cooker and return the skillet to the heat. Combine the wine and mushrooms to the skillet; cook until the mushrooms begin to absorb the wine; pour the mixture into the slow cooker.
Place the cover on the slow cooker and set to High; cook for one hour. Reduce heat to Low and cook until the beef is fork-tender, 6 to 8 hours. Whisk together the warm water and cornstarch; stir into the stew; cook uncovered until stew thickens, about 15 minutes.