Nan's Secret! Instant Pot Slow Cooker Pot Roast Magic

Ingredients

• 3 lb (1.36 kg) beef chuck roast
• 1 tbsp (15 ml) olive oil
• 1 large yellow onion, chopped (approx. 1 1/2 cups)
• 2 cloves garlic, minced
• 1 (1 oz/28g) package dry onion soup mix
• 1 tsp (5 ml) dried thyme
• 1/2 tsp (2.5 ml) dried rosemary
• 1/2 tsp (2.5 ml) black pepper
• 1 (14.5 oz/411g) can diced tomatoes, undrained
• 1 cup (237 ml) beef broth
• 2 tbsp (30 ml) Worcestershire sauce
• 4 medium carrots, peeled and cut into 1-inch pieces (approx. 2 cups)
• 4 medium potatoes, peeled and cut into 1-inch pieces (approx. 4 cups)
• 2 celery stalks, chopped (approx. 1 cup)