The Best Fix-It-And-Forget-It Beef Stew

INGREDIENTS
1 large onion
2 medium carrots, peeled and thinly sliced
2 large potatoes, cut into 1/2″ chunks
1 cup fresh green beans cut into bite-sized pieces
1lb stew-meat beef chunks
1 bay leaf
1 teaspoon fresh thyme
1 clove garlic, crushed
3 cups beef stock
2 tablespoons light brown sugar
3/4 teaspoon salt
2 teaspoons Worcestershire sauce
Pepper to taste
3 tablespoons flour
2 teaspoons tomato paste

PREPARATION
Put the ingredients except for the flour and tomato paste into the slow cooker and stir to combine.
Cover and cook on low for 8 to 9 hours or high for 4 to 5 until the beef is tender and potatoes are fork-tender.
Stir the stew once or twice as it cooks if possible.
30 minutes before serving, transfer a ladle-ful of broth to a small mixing bowl.
Add the flour and tomatoe paste. Whisk until mooth, then stir the mixture back into the stew and cook for the remaining half hour.
Serve hot.