In a large skillet, warm the oil over medium heat. Add the onions, carrots, and celery, and sauté, stirring regularly, until the vegetables are tender, about 10 minutes.
1 tbsp. olive oil, 1 large yellow onion, diced small, 3 medium carrots, sliced into coins , 3 celery stalks, sliced into 1/4" pieces
Transfer the mixture to a 6–7 quart slow cooker, and add the beef, tomatoes, broth, garlic, salt, and pepper. Stir to combine
2 lbs. beef chuck roast, fat well-trimmed, cut into 1" pieces, 1 can (28 oz.) crushed tomatoes, 1 cup low-sodium chicken broth, 3 cloves garlic, minced, 1 tsp. kosher salt, 1/4 tsp. ground black pepper
Cover the slow cooker and set it to cook on high for 6 hours, stirring gently every 1-1/2 hours to enhance the flavors.
To serve, portion out the brown rice and ladle the stew into six bowls. Finish each with a dollop of sour cream and a sprinkle of minced parsley.
sour cream, minced parsley