Start by taking your beef chuck roast out of the refrigerator to reach room temperature, around 30 minutes. Pat the roast dry with paper towels, then generously season it with salt and pepper. Dust the seasoned roast with all-purpose flour.

Heat 2 tablespoons of olive oil in a Dutch oven over medium-high heat. Once hot and shimmering, carefully add the seasoned roast and sear for 3-4 minutes on each side until evenly browned. Remove the roast from the pot and set aside.

In a measuring cup, whisk together 2 cups of beef stock, 1 cup of bold red wine, 2 tablespoons of Dijon mustard, and 1 packet of onion soup mix. Set it aside.

Chop the leeks, yellow onion, carrots, and baby potatoes into even-sized pieces. Add these vegetables to the Dutch oven, creating a cozy bed for your pot roast. Sprinkle minced garlic over the vegetables.

Nestle the seared roast back into the center of the vegetables. Pour the prepared braising liquid over the roast and veggies. Cover the Dutch oven and place it in a preheated oven at 350°F, allowing it to braise for 3 to 3.5 hours, checking for tenderness occasionally.

Once the pot roast is fork-tender, carefully remove the meat and vegetables. To make gravy, whisk together 2 tablespoons of cornstarch with 2 tablespoons water into the remaining liquid, simmering until thickened to your liking.