Easy Cast Iron Flank Steak

5 from 28 votes

Easy Cast Iron Flank Steak

This easy Cast Iron Flank Steak is made with a delicious, herby chimichurri butter that elevates every bite. Perfectly seared in the pan, this steak is juicy and tender and a great option for date night dinners! Simply pair it with your favorite sides, like mashed potatoes or roasted vegetables, for a more filling meal.

Prep Time5

Cook Time15

Total Time20

Course: Main

Cuisine: American

Servings: people

Calories: 291kcal

Author: Brianna May

Equipment

Ingredients

grape seed oil
1.5-2 pounds flank steak, about 1-1.5 inches thick
2 heaping teaspoons Morton kosher salt*
1 teaspoon pepper
1 teaspoon granulated garlic
Chimichurri Butter
2 Tablespoon salted butter, room temperature
1 Tablespoon chopped fresh parsley
½ teaspoon lemon zest
¼ teaspoon chili flakes
3 cloves garlic
a few sprigs fresh thyme & oregano

Instructions

In a small bowl, mix together the butter, parsley, lemon zest, and chili flakes. Set aside.
2 Tablespoon salted butter, room temperature, 1 Tablespoon chopped fresh parsley, ½ teaspoon lemon zest, ¼ teaspoon chili flakes
In another small bowl, combine the salt, pepper, and minced garlic.
2 heaping teaspoons Morton kosher salt*, 1 teaspoon pepper, 1 teaspoon granulated garlic
Rub both sides of the steak with the salt mixture.
Heat a generous amount of grape seed oil in a cast iron pan over high heat until shimmering.
grape seed oil
Carefully place the steak in the center of the hot pan without moving it. Sear for 3-4 minutes until a crust forms.
1.5-2 pounds flank steak, about 1-1.5 inches thick
Flip the steak and sear the other side for another 3-4 minutes.
Reduce the heat to medium and continue cooking until the steak reaches an internal temperature of 125-130 degrees Fahrenheit, about 1-2 minutes more per side.
While the steak cooks, fry the garlic cloves, oregano, and thyme sprigs in the oil until golden. Remove them from the oil and place on a cutting board.
3 cloves garlic, a few sprigs fresh thyme & oregano
Let the steak rest on the cutting board for about 5-10 minutes.
While the steak rests, chop the fried herbs and garlic.
Using a fork, mix the chopped herbs and garlic with the butter mixture from Step 1.
Chimichurri Butter
Spread the herb-infused butter over the rested steak and sprinkle with a pinch of salt before slicing against the grain.

Video

Notes

Kosher Salt: All of my recipes are tested with Morton kosher salt unless noted otherwise. It is the best salt for everyday cooking because of its size and flavor. If using table salt, the amount should be reduced. I highly recommend picking up some kosher next time you are at the store!
Be generous with the salt. Since flank steak is a leaner piece of meat, adding a generous amount of salt will help create more tender slices. It also adds a delicious taste to the steak.
Use a high smoke point oil. The best cast iron steak is seared on a high temperature. To achieve this, you’ll need to use a high smoke point oil so it can withstand the higher temp.
Do not overcook the steak. Because flank steak is lean, you'll dry out the steak if you overcook it. Be sure to check the flank steak cast iron time as you sear/cook the steak. It should only take about 7-10 minutes in total. You can also check the internal temperature before you remove flank steak from the stove to be sure it's properly cooked.
Allow the steak to rest. Allowing the steak to rest after cooking lets the internal liquids redistribute for a juicier, tender flank steak.
Slice the meat against the grain. This particular slicing method helps provide more tender pieces of cast iron flank steak. If you cut with the grain, you’ll notice steak pieces that are tougher to chew.
Add other fresh herbs – Chimichurri butter can be made with various fresh herbs, including basil. Don’t be afraid to experiment with the herb butter in this cast iron flank steak dish.
Make a simpler herb butter – If you're short on time, you can keep it simple by chopping fresh herbs like oregano and parsley to mix with the butter. This herb butter will still add delicious flavor to the recipe.
Use a different steak cut – If you're not on a tight budget, you can create a more indulgent recipe with other cuts like filet mignon, tomahawk, or ribeye. These steaks will also taste great with the chimichurri butter.

Nutrition