Drunken Garlic Pot Roast

1 (2 1/2 pound) boneless beef chuck roast, trimmed of fat
2 tablespoons vegetable oil, divided
1/2 teaspoon salt
1/4 teaspoon pepper
2 medium onions, thinly sliced
24 cloves garlic, minced (about 4 tablespoon)
2 beef bouillon cubes
1/2 cup hot water
1 cup lager beer
3 tablespoons brown sugar
1 tablespoon Dijon mustard
1 tablespoon cider vinegar
Cornstarch dissolved in water, for gravy

In a large skillet, heat 1 tablespoon of the oil and brown roast on both sides, seasoning with salt and pepper; remove to a platter and keep warm.

Add the remaining tablespoon oil to the pan and add the onions. Cook until they just start to wilt, then add the garlic. Cook until the onions are tender, a few minutes more.

Add the bouillon cubes to the hot water and stir to dissolve; add to the skillet along with the beer, brown sugar and vinegar; stir to mix well. Pour mixture into a crockpot. Place roast on top of liquid, cutting into pieces if it doesn't lay flat. Cook on LOW for 7 to 8 hours.

Remove meat from crockpot and pour liquid into a saucepan; heat to a boil, and mix a slurry out of the cornstarch and water; thicken pan liquid with slurry to make a gravy.

Serve gravy over meat with potatoes or noodles.