Step 1

Heat oil in a large skillet or pan over high heat. Season roast with a good amount of salt and pepper. Sear on all sides until browned (about 5-6 minutes each side). Transfer roast to the bowl of a 6-quart slow cooker.

Step 2

Add the onions, garlic, potatoes, carrots, celery, balsamic, mustard, brown sugar, thyme and bouillon. Season with salt and pepper to taste. Mix the stock together with the flour and pour into the slow cooker bowl (don't worry about any lumps, they will cook out).

Step 3

Cook on low setting for 8 hours, or until meat is tender and falling apart and the vegetables are soft.

Step 4

Taste test and add any extra balsamic vinegar, brown sugar, salt or pepper, if needed.

Step 5

Slice meat, garnish with parsley and drizzle with gravy.

Step 6

Season roast with a good amount of salt and pepper. Heat oil in the Instant Pot and set to 'Saute'. When oil is hot, sear on all sides until browned (about 4-5 minutes each side).

Step 7

Add the onions, garlic, potatoes, carrots, celery, balsamic, mustard, brown sugar, thyme and bouillon. Season with salt and pepper to taste. Mix the stock together with the flour and pour into the slow cooker bowl (don't worry about any lumps, they will cook out). Place lid on Instant pot with steam valve closed.

Step 8

Change Instant Pot setting to 'manual' mode for 60 minutes on 'high' pressure.

Step 9

When time is up and cooker beeps, turn off and allow pressure to release naturally for 15 minutes. After 15 minutes, use the quick pressure lever to release any remaining pressure. Carefully remove lid and transfer roast and veggies to a warm plate.

Step 10

Preheat oven to 350°F (175°C). Heat oil in a dutch oven or heavy based oven-proof pot over medium-high heat. Season roast all over with a good amount of salt and pepper. Sear until brown on all sides (about 4-5 minutes each side).

Step 11

Transfer roast to a plate. Sauté garlic for 30 seconds until fragrant. Add the stock and balsamic vinegar to deglaze your pan, scraping up any browned bits. Whisk in the flour and let cook for about 4 minutes (don't worry about any lumps, they will cook out).

Step 12

Add the onions, garlic, potatoes, carrots, celery, mustard, brown sugar, thyme and bouillon. Season with salt and pepper to taste.

Step 13

Bring to a simmer, cover with lid (or foil) and transfer to the oven. Roast for 3-4 hours until the meat is tender and falling apart. (Check roast after 1 1/2 hours. If the liquid has mostly been absorbed, add 2 cups extra broth and continue cooking.)

Step 14

Transfer the roast, carrots, and potatoes to a warm plate. With a spoon, skim the fat off the surface of the cooking liquid. Cut the roast into thick slices, and serve with the vegetables. Pass the pan juices separately.