Preheat a multi cooker with a browning option with a drizzle of olive oil (or if your slow cooker doesn't have a browning function you can sear meat in a skillet instead).

Season 2-3 lbs chuck roast with 1 teaspoon of kosher salt, 1 teaspoon black pepper, and 1 teaspoon of garlic powder.

Place roast into hot pan and brown on all sides.

Whisk 1 1/2 cups hard cider, 1 cup beef stock, 2 tablespoons of tomato paste, and 2 tablespoons of Worcestershire sauce together.

Change the function on the multicooker to slow cook on low setting (or in a regular crockpot set to low).

Pour the hard cider mixture into the cooker with the roast.

Add 1 large sliced sweet onion, 6-9 large carrots cut into 2-inch chunks, 1 lb of Yukon gold potatoes or sweet potatoes, and 2 sprigs of fresh thyme.
I used a few large handfuls of rainbow-colored medium to small-sized carrots from my garden.

Slow cook for 8 hours until meat is tender.

Remove roast from slow cooker, set aside.

Remove potatoes, carrots, and onions from the slow cooker as well and cover with foil along with the beef.

Discard thyme sprigs.

In a small bowl combine 1/2 cup of cold water and 2 tablespoons of cornstarch to make a slurry then add to the cider broth.

Bring to a boil.

Reduce heat and simmer, stirring constantly for 10 Minutes to 15 Minutes or until desired thickness.

Salt and pepper to taste.

Shred beef and coarsely chop vegetables, toss together, and set aside.

Butter each slice of bread and spread with a thin layer of mayonnaise. The mayonnaise will keep the bread from burning.

Layer slices of sourdough bread with a slice of Muenster Cheese, and pile high with the chopped pot roast mix. Top with more Muenster Cheese and remaining slices of bread.