Although many crock pot stew recipes call for adding the beef raw, I think browning it gives it a much richer flavor.
For the five minutes it takes to do, browning the meat is well worth it in my opinion. Toss this together one morning and see for yourself.

1 1/2 pounds boneless lean beef, cubed
3 tablespoons vegetable oil
1 teaspoon salt
1 teaspoon ground black pepper
2 teaspoons garlic powder
3 (10.5 ounce) cans beef broth
6 cups water
4 stalks celery, chopped
6 carrots, chopped
6 green onions, chopped
1/2 cup chopped fresh parsley
1 cup barley
1 teaspoon dried thyme
In a skillet over medium heat, saute the beef in the oil for 5 minutes, or until browned. Stir in the salt, pepper and garlic powder and place seasoned meat in a slow cooker. Add a little water to the skillet and stir to pick up the browned bits. Add to the slow cooker.
Add the broth, water, celery, carrots, green onions, parsley and barley. Cover and cook on low setting for 6 to 8 hours, or until the vegetables and barley are tender. Add the thyme just before serving.