Step 1

Use a good-quality, medium-bodied wine, such as a Côtes du Rhône or a Pinot Noir, for this dish.

Step 2

Adjust oven rack to lower-middle position and heat oven to 300 degrees. Pat beef dry with paper towels and season with salt and pepper. Heat 2 tablespoons oil in Dutch oven over medium-high heat until just smoking. Add both beef roasts and brown on all sides, 7 to 10 minutes; transfer to large plate.

Step 3

Add remaining 1 tablespoon oil, onion, and celery to now-empty pot and cook over medium heat until vegetables are softened, 5 to 7 minutes. Stir in garlic, sugar, and thyme and cook until fragrant, about 30 seconds. Stir in broths and water, scraping up any browned bits.

Step 4

Add browned roasts and any accumulated juices to pot and bring to simmer. Cover, transfer pot to oven, and cook for 2 hours, flipping roasts halfway through cooking.

Step 5

Remove pot from oven. Nestle carrots into pot around meat and sprinkle potatoes and parsnips over top. Return covered pot to oven and cook until meat and vegetables are very tender, 1 to 1½ hours.

Step 6

Remove pot from oven. Transfer roasts to carving board, tent loosely with aluminum foil, and let rest while finishing sauce. Transfer vegetables to large bowl, season with salt and pepper to taste, and cover to keep warm.

Step 7

Using large spoon, skim any fat from surface of braising liquid. Stir in wine and simmer until sauce measures 2 cups, about 15 minutes. Season with salt and pepper to taste. Transfer vegetables to serving platter. Remove twine from roasts, slice meat against grain into ¼-inch-thick slices, and transfer to platter with vegetable. Spoon half of sauce over meat. Serve, passing remaining sauce separately.