Step 1

1 (Optional) Marinate flank steak for 24 hours prior. Flank steaks take marinade very well and it can even help make the meat more tender.

Step 2

2 Pre-heat water bath to your ideal temperature (see chart on the side). We prefer 130u00b0F since flank steaks do not have much fat to render.

Step 3

3 Generously season with sea salt, cracked black pepper, and any aromatics such as rosemary.

Step 4

4 Vacuum seal the flank steak or place it in a heavy duty Ziploc bag using the water displacement method.

Step 5

5 Place bagged flank steak in water bath and cook for 1 - 2 hours (closer to 2 hours if steak is extra thick).

Step 6

6 Remove flank steak and pat dry with paper towels.

Step 7

7 Pre-heat cast iron pan on medium-high heat and add avocado oil (or another high smoke point oil).

Step 8

8 Sear steak on hot cast iron pan for approximately 1 minute, flipping every 15 seconds.

Step 9

9 Add butter and any aromatics to the pan for added flavor and crispness. Sear for an additional 30 seconds.

Step 10

10 (Optional) Break out the searing torch if you're feeling adventurous for a perfect crust.

Step 11

11 Before serving, use a spoon to top the flank steak with the leftover juices and butter from the pan - this will help further develop the crust and add flavor.

Step 12

12 Cut against the grain in very thin slices.