This succulent, tender crock pot London broil with au jus is slow-cooked to perfection and only takes ten minutes prep. Cooked low and slow, the roast is perfect as is with rice or potatoes, but it also makes a delicious sandwich with au jus for dipping.
This fork-tender roast can be started in the morning and ignored all day until you are ready to eat. If you'd like gravy, prepare it with the drippings just before serving, or use the drippings for an au jus for dipping. If you have leftovers, try this delicious leftover London broil recipe!
What you need to make Crock Pot London Broil
- London broil roast. Traditionally London broil was a preparation method involving marinating and grilling or broiling but has come to refer to a cut of meat. London broil is a lean cut of beef, making it a great option for slow cooking to retain juices and prevent drying out. The cut of meat labeled as London broil is typically top round or flank steak, which are both lean, rear cuts. Slow cooking London broil eliminates the need for marinating since the roast cooks in its own juices for an extended period of time.
- Salt & pepper.
- Fresh garlic. Fresh garlic is sliced and inserted into slits in the roast for maximum flavor.
- Onion. I prefer yellow onions for this recipe, but Sweet Vidalia onions could be used.
- Soy sauce or tamari. I always use tamari instead of soy sauce in recipes except those calling for over a half a cup of soy sauce (such as marinades). Tamari is fermented for longer, tastes richer and is less salty, and delivers more umami in recipes.
See recipe card for quantities.
How to make Crock Pot London Broil
Season the roast with salt and pepper on both sides.
Cut slits in one side of the roast and insert slices of garlic into each slit.
Layer half of the sliced onions on the bottom of the crock pot.
Place the seasoned roast on top of the onions, top with the water and soy sauce/tamari, then place the remaining onions on top of the roast.
Cook on low for 8-10 hours. Remove from the crock pot and let the roast rest until the internal temperature is about 120ºF before slicing (see slicing tips below).
You may serve it au jus (in its own juices) or make a gravy if desired.
For gravy, mix equal amounts of cornstarch and cool water to form a smooth paste. Pour the drippings from the crockpot into a saucepan and add the cornstarch mixture, whisking until smooth. Continue cooking at a simmer, stirring frequently, until thickened.
Time needed & crockpot cooking time tips
The thing I love most about this recipe is that you can get it started with under 10 minutes prep time, and it requires almost no work to get it ready to serve at dinner time. If you want to make a gravy with the juices, plan for about 5 minutes (but it's perfect if you choose to just serve it au jus).
Note that crockpots all cook at different rates based on the combination of the size of the crockpot, the weight of the roast, and sometimes even just the brand of the cooker.
The larger the crockpot, the hotter it tends to cook, so you will need to adjust the cooking time based on your crockpot and the size roast you buy. If you have a 6-quart crockpot and use a 2-pound roast, you will have an entirely different cooking time than if you have a 3-quart crockpot and a 2-pound roast.
If you want a specific degree of doneness (for example, if you want to be able to slice without any shredding or be able to use strips of leftover meat in our popular beef and broccoli stirfry), 8-10 hours on low might be too long in your particular crockpot.
I have yet to encounter meat that doesn't eventually shred if it is cooked long enough at low temperature, so you may need to check it earlier in the process (starting at 5-6 hours) to get the correct degree of doneness if you want a more firm roast. 8-10 hours will result in a well-done roast that tends to shred.
You may use the slow cooker function of an Instant Pot for this recipe, but be aware that the Instant Pot slow cooker function cooks only from the bottom and not from the sides like a crockpot appliance. You can also cook this London Broil recipe in a covered Dutch oven in a slow oven (cook at 250ºF for 2-3 hours, checking for the desired amount of tenderness after two hours).
- Rest the meat before slicing for the most tender, juicy result. The Food Lab at Serious Eats gives you insight into the science behind why resting meat is important, so I won't try to go in-depth here. Suffice it to say that it's more about cooling the meat (according to Serious Eats, 120ºF is the optimal internal temperature) enough to allow the juices to redistribute among the relaxing muscle fibers of the roast.
- Make sure your knife is sharp, and/or use a serrated knife. My favorite carving knife is an old Quikut multipurpose knife with a white plastic handle that was passed down from my grandmother. I'm pretty sure it was swag from a bank or grocery store back in the 70s, because both of my grandmothers had them.
- Very tender meat holds its shape better if it is sliced when cold, so to use leftovers in stir fry, make sure you leave the leftover roast unsliced and slice it when it is cold just before preparing the stir fry.
- Gluten-free. Make sure to use a gluten-free soy sauce if you are following a gluten-free diet. Otherwise, this recipe is gluten-free.
Storage and freezing
Crock Pot London Broil is great as leftovers, especially with au jus for dipping. It keeps well in an airtight container for up to four days in the refrigerator.
Do not slice the leftover meat before storing. It will slice much easier when it is cold (it is so tender that it tends to shred if you slice it when it is hot), and an unsliced roast will lose less moisture during storage than a sliced roast.
I never have enough leftover slow cooker London Broil to freeze, but if you would like to freeze it, it will maintain its texture and flavor for up to 3 months in the freezer if it is stored in an airtight (preferably vacuum sealed) container.
Try London Broil Au Jus with these sides
When I make London Broil in the crock pot with au jus, I like to serve it with mashed potatoes or white rice and a simple green vegetable.
Crockpot London Broil with Au Jus
- 2 pounds London broil
- salt and pepper, to taste
- 1 clove garlic
- 1 onion
- ¾ cup water
- 3 tablespoons soy sauce or tamari
- Season 2 pounds London broil with salt and pepper to your preference.
- Slice 1 onion and 1 clove garlic.
- Make small slits in the roast and insert slices of garlic cloves.
- Place about half of the sliced onion in the crock-pot and put roast on top of onions. Top roast with the ¾ cup water and 3 tablespoons soy sauce or tamari. Arrange the remaining onion slices on top of the roast.
- Cover and cook on low for about 8-10 hours (time varies with individual crockpots, see notes).
- When roast is tender and ready to serve, place on a serving platter. Let rest until internal temperature is about 120°F before slicing.
- Serve with the juices or make a gravy if desired.
- To make gravy, blend 2 tablespoons cornstarch with 2 tablespoons of cold water. Form a smooth paste. Pour drippings from crockpot pan into a saucepan and add cornstarch mixture, whisking until smooth. Continue cooking at a simmer, stirring frequently, until thickened.
- For slicing, make sure your knife is sharp, and/or use a serrated knife.
- Very tender meat holds its shape better if it is sliced when cold, so to use leftovers in stirfry, make sure you leave the leftover roast unsliced and slice it when it is cold just before preparing the stirfry.
- For gravy, be sure to use cool water when mixing the cornstarch slurry.
- Make sure to use a gluten-free soy sauce if you are following a gluten-free diet. Otherwise, this recipe is gluten-free.
- If you have leftovers, try our popular delicious Beef and Broccoli Stirfry recipe!