Cast-Iron Flat Iron Steak with Garlicky Mushroom Ragù over Soft Parmesan Polenta

Steps

1. Step 1

   Season the steak all over with the kosher salt and pepper and leave it on a plate at room temperature while you start the polenta and mushrooms.

   • 1 1/2 lb flat iron steak
   • 1 1/4 tsp kosher salt
   • 1/2 tsp black pepper
2. Step 2

   Bring the water and salt to a boil in a medium saucepan. Pour in the cornmeal in a slow stream while whisking constantly so it doesn't clump.

   5 min

   • 4 cups water
   • 1 tsp salt
   • 1 cup coarse cornmeal (polenta)
3. Step 3

   Turn the heat to low and cook the polenta, stirring with a wooden spoon every few minutes and scraping the bottom, until thick, smooth and no longer gritty, about 30 minutes. If it gets stiffer than soft mashed potatoes, whisk in a splash of hot water.

   30 min, hands-off

4. Step 4

   Meanwhile, heat the olive oil in a large skillet over medium-high heat. Add the mushrooms and spread them out. Cook without stirring for 4 minutes, then stir and keep cooking until they have released their liquid and are deeply browned, 8 to 10 minutes more.

   14 min

   • 2 tbsp olive oil
   • 1 1/4 lb mixed mushrooms (cremini, shiitake, oyster)
5. Step 5

   Add the shallot, garlic and chopped rosemary and cook, stirring, until fragrant and softened, about 2 minutes. Stir in the tomato paste and cook 1 minute more.

   3 min

   • 1 small shallot
   • 4 cloves garlic
   • 1 tsp fresh rosemary
   • 1 tbsp tomato paste
6. Step 6

   Pour in the broth and balsamic vinegar, scraping up the browned bits. Simmer until the liquid is glossy and slightly reduced but still brothy, 5 to 6 minutes. Stir in the butter and parsley, season with salt and pepper, and keep warm over low heat.

   6 min

   • 1 1/4 cups beef or mushroom broth
   • 1 tbsp balsamic vinegar
   • 1 tbsp unsalted butter
   • 2 tbsp fresh parsley
   • salt and black pepper
7. Step 7

   Heat a cast-iron skillet over medium-high heat until very hot, about 3 minutes. Add the neutral oil, then the steak. Sear without moving it for 4 minutes, until a dark crust forms.

   7 min

   • 1 1/2 lb flat iron steak
   • 1 tbsp neutral oil, such as canola
8. Step 8

   Flip the steak, add the butter and rosemary sprigs, and cook 3 to 4 minutes more, tilting the pan and spooning the foaming butter over the top, until an instant-read thermometer in the thickest part reads 130°F for medium-rare.

   4 min

   • 1 tbsp unsalted butter
   • 2 sprigs fresh rosemary
9. Step 9

   Move the steak to a cutting board and let it rest 8 to 10 minutes. Don't skip this or the juices run out.

   9 min, hands-off

10. Step 10

    Finish the polenta: off the heat, stir in the Parmesan, butter and milk until creamy and pourable. Taste and add salt if needed.

    2 min

    • 3/4 cup Parmesan
    • 3 tbsp unsalted butter
    • 1/4 cup whole milk or heavy cream
11. Step 11

    Slice the steak thinly against the grain. Spoon polenta into shallow bowls, lay the steak over it, and spoon the mushroom ragù and its broth over the top.

    5 min

Where it’s from

Written by AI from an idea

Version 1, saved Oct 5, 2026