Coat meat with a mixture of flour, salt, and pepper.
Add about 1 tablespoon butter to a large 5.3-6 quart Dutch oven* and brown one third of the meat quickly on all sides on medium high heat. Remove and set aside. Repeat adding butter and meat, until all beef is browned and set aside.
In the same Dutch oven, sauté onion and carrot on medium heat for about 3 minutes until lightly browned (add more butter if needed). Add garlic, sauté for 1 minute, then add tomato paste and cook for 1 minute. Add 1 cup of wine and deglaze the bottom of the pan, scraping up any browned bits.
Remove from heat. Add beef on top of the vegetables in the Dutch oven.
Heat cognac, pour over beef, and ignite. When flame goes out, add about 1 cup of red wine, beef broth, and return to medium heat to bring to a boil. Once it starts boiling, lower heat to bring the stew to a simmer.
Meanwhile, in a separate skillet, heat 1 tablespoon olive oil on medium high, and sauté pearl onions until browned, about 6-8 minutes. Add to Dutch oven.
In the same skillet, add remaining olive oil and saute mushrooms until browned, 6-8 minutes. Add to Dutch oven.
Add half of the parsley, and all of the thyme, bay leaf, and marjoram to the Dutch oven and stir, continuing to simmer.
Combine remaining wine with cornstarch, and add the slurry to the Dutch oven, stirring to combine.
Cover and bake for 2-2 ½ hours, until meat and vegetables are tender, checking after about 1 ½ hours. Add additional wine or broth if the stew is too thick. Bake up to 3 hours for richer sauce or if beef is not yet tender.
Garnish with remaining parsley and serve over mashed potatoes.
*If you don’t have a Dutch oven, brown meat in a large skillet, and place in a large (6 quart) casserole dish. Then brown onion, carrots, and garlic, and add to casserole dish. Add remaining ingredients and bake.