Servings: 6

2 pounds top round steak or flank steak 2 pounds top round steak or flank steak
3 tablespoons balsamic vinegar 3 tablespoons balsamic vinegar
1 tablespoon honey 1 tablespoon honey
3 tablespoons soy sauce 3 tablespoons soy sauce
2 tablespoons Worcestershire sauce 2 tablespoons Worcestershire sauce
2 tablespoons olive oil, divided 2 tablespoons olive oil, divided
3 garlic cloves, smashed 3 garlic cloves, smashed
2 teaspoons mustard 2 teaspoons mustard
1 tablespoon butter, unsalted 1 tablespoon butter, unsalted
salt and pepper to taste salt and pepper to taste
 
Equipment: subheading: Equipment:
Duo-IP or Aura Pro or Accu-SV800 Duo-IP or Aura Pro or Accu-SV800
Ziplock bag (gallon) or FoodSaver Ziplock bag (gallon) or FoodSaver

Marinate the steak: subheading: Marinate the steak:
In a zip-lock bag, add balsamic vinegar, honey, soy sauce, Worcestershire sauce, garlic, 1 tablespoon of olive oil, and mustard. Mix well.
Add top round steak to the bag, close the bag and coat the meat thoroughly. Let it marinate for 2 hours in the refrigerator.
Sous Vide: subheading: Sous Vide:
In the meantime, add water to the sous vide container or Duo-SV, set it to 132°F
Remove the steak from the marinade and place it in a new zip-lock bag (discard the marinade). Place the butter in the middle of the meat.
Seal all but one corner of the bag, and slowly place it in the water bath. Make sure everything below the zip-line is covered by water. Then seal the rest of the bag. This is called the water displacement method.
Make sure the steak is fully submerged while the top seams of the ziplock bag is above the water.
Cook for 6 hours. I’ve also pushed this to 8 hours with the same great results.
Finishing: subheading: Finishing:
When your steak has completed cooking in the IP, remove the bag from the water bath and transfer it to an ice bath or refrigerator. Let it chill for about 10 minutes.
Remove the steak from the ziplock bag and wipe off the moisture with paper towels.
Season with more salt and pepper if necessary. Brush the steak with oil.
Place the cast-iron skillet or grill on medium-high heat. Once very hot, add the steak and sear about 1 minute per side.
Slice against the grain and serve with potatoes and veggies.

Fun Fact: London broil, despite what you might find at the local meat market, is not a cut of beef. Rather it is a method of cooking a steak.  Fun Fact: London broil, despite what you might find at the local meat market, is not a cut of beef. Rather it is a method of cooking a steak.
Fun Fact: London Broil was one of the first recipes to become popular in early restaurants in the United States and so the name London broil became synonymous with a cut of meat.  Fun Fact: London Broil was one of the first recipes to become popular in early restaurants in the United States and so the name London broil became synonymous with a cut of meat.
Fun Fact: If you order London Broil whilst in London, England, they will look at you like a silly American tourist.  Fun Fact: If you order London Broil whilst in London, England, they will look at you like a silly American tourist.