slow cooker barley-beef soup

Ingredients

• 12 ounces beef stew meat, cut into 1-inch cubes
• 1 tablespoon cooking oil
• 3 cans (10-3/4 oz.) beef broth
• 1 cup chopped onion (1 large)
• 1/2 cup chopped celery (1 stalk)
• 1 teaspoon dried oregano or basil, crushed
• 1/4 teaspoon black pepper
• 2 cloves garlic, minced
• 1 - bay leaf
• 1 cup frozen mixed vegetables
• 1 can (14-1/2 oz.) diced tomatoes, undrained
• 1 cup 1/2-inch slices peeled parsnip - or - 1/2-inch cubes peeled potato
• 2/3 cup regular barley (not quick-cooking)