Classic Slow Cooker Pot Roast

3 to 4 pounds beef chuck roast

4 medium carrots, cut into chunks

3 medium potatoes, cut into chunks

1 medium onion, chopped

3 cloves garlic, minced (optional)

1 cup beef broth

2 tbsp tomato paste (optional)

1 tsp dried thyme

1 tsp dried rosemary

Salt and freshly ground black pepper, to taste

2 tbsp olive oil or vegetable oil

Instructions: