Season the 3 pounds sirloin steaks with 1 teaspoon kosher salt and 1/2 teaspoon black pepperon all sides (these salt and pepper measurements are not per steak, this is the total amount of seasoning to use on the steaks.)
In a large skillet over medium heat, add half of the oil and sear the steaks until golden brown. You will need to do this in batches, and add more oil if needed.
Place the steaks into the bottom of a 6-8 quart slow cooker.
Do not wipe out the pan, add the 1 medium onion, small diced cook until softened, 6-8 minutes
Add the 4 cloves garlic, minced and cook until fragrant, 30 seconds.
Add the onions and garlic over the steaks in the slow cooker.
In a small bowl, whisk together the 2 (0.87 ounce) low sodium brown gravy packets with 2 cups water. Add 1 Tablespoon Worcestershire sauce.
Pour the sauce mixture over the steaks.
Cook on low for 5-6 hours or high 3-4 hours until the meat is tender. It is recommended to cook on low for best (most tender) results.NOTE: Do not remove the lid while cooking. This negates the whole purpose of using a slow cooker. Set it and forget it. Opening the lid to check on the meat will result in a longer cooking time and the meat will not come out as tender.
When done, take the steaks out of the slow cooker and set aside.
In a large skillet over medium heat, melt 2 Tablespoons unsalted butter.
Once melted, whisk in 2 Tablespoons all-purpose flour and cook for 2 minutes whisking often.
Slowly stream in the cooking liquid from the slow cooker and whisk to combine, this will avoid lumps.
Simmer for 4-5 minutes until thickened.
Add the steaks back to the slow cooker, pour the gravy on top. Keep warm until ready to serve.
Notes
Please refer to my FAQ’s (Frequently Asked Questions) and ingredient list above for other substitutions or for the answers to the most common questions.
This recipe can be cut in half. See the FAQ's above in the post on how to do that.