Creating the incredible Slow Cooker Beef Manhattan is simple if you follow these clear-cut steps:

1. Sear the Beef: In a large pan over medium-high heat, add olive oil. Once hot, sear the beef cubes until browned on all sides. Remove from the heat and set aside.

2. Sauté Aromatics: In the same pan used to sear the beef, add diced onions and garlic. Sauté until softened and fragrant, about 3–4 minutes.

3. Combine Ingredients: In the slow cooker, add the seared beef, sautéed onions, and garlic. Then, pour in the beef broth, Worcestershire sauce, and tomato paste.

4. Add Seasonings: Stir in dried thyme, dried rosemary, carrots, and celery. Season with salt and pepper to taste.

5. Set the Slow Cooker: Cover the slow cooker and set it on low for 6 to 8 hours or high for 4 to 5 hours, depending on your available time.

6. Thicken the Gravy (Optional): If you prefer a thicker gravy, mix cornstarch with a bit of cold water in a small bowl. One hour before serving, stir this mixture into the slow cooker.

7. Prepare for Serving: Once cooked, taste and adjust seasonings if necessary. Stir to combine all flavors.

8. Garnish: Serve hot, garnished with freshly chopped parsley for a touch of color.

These clear instructions will help you create a mouthwatering Slow Cooker Beef Manhattan that everyone will adore.