Roast Beef

Lightly season the beef with salt and pepper on all sides; preheat the oven to 350°F.

In a large, deep ovenproof pot or Dutch oven, heat the olive oil over medium-high heat. Sear each side of the beef, about 5 minutes per side. Drop the onion in the pot around the beef, and add the thyme. Add enough water to come about an inch up the side of the beef. Cover the pot and put it in the oven.

Cook for about 3 hours, checking each hour to maintain the water level and adding more if necessary.

Carefully transfer the roast to a cutting board and let rest for 15 to 20 minutes.

Remove and discard the thyme stems. Put the pot over medium-high heat. In a bowl, whisk together the flour and water. When the broth is boiling, whisk in the flour mixture and continue to whisk until the gravy thickens. Scrape any bits off the bottom of the pot. That's the "debris." Taste and adjust the seasoning if necessary. Take the gravy off the heat and set aside. 

Slice the beef against the grain into ¼-inch slices. It may fall apart. That’s fine.

That's more debris.

Sandwiches

Spread one half of each piece of bread with mayo.

Dip slices of beef in the gravy and add them to the sandwiches. Top the meat with tomato, lettuce, and pickle chips, then add the top piece of bread and serv