Pan-Seared Hanger Steak with Balsamic Mushroom Sauce, Herb-Roasted Fingerling Potatoes and Garlic Broccolini

Preheat oven to 425°F (220°C).

Remove the hanger steak from the refrigerator 30 minutes before cooking to bring to room temperature. Pat dry with paper towels and season generously with 1 tsp kosher salt and 1/2 tsp black pepper on all sides.

Wash and halve the fingerling potatoes lengthwise. Place on a baking sheet, drizzle with 2 tbsp olive oil, 1 sprig chopped rosemary, 2 sprigs thyme leaves (removed from stems), 1/2 tsp kosher salt, and 1/4 tsp black pepper. Toss to coat evenly.

Arrange potatoes cut-side down on the baking sheet and roast for 25-30 minutes until golden and crisp on the outside, tender inside.

While potatoes are roasting, clean and slice mushrooms into 1/4-inch slices. Peel and finely dice the shallots. Peel and mince 3 garlic cloves, leaving 1 clove for the broccolini.

Wash the broccolini and trim the tough ends. Set aside.

Heat a large cast iron skillet over high heat. Add 1 tbsp olive oil. When oil is shimmering and almost smoking, carefully place the steak in the pan. Sear undisturbed for 4 minutes to develop a deep brown crust.

Flip steak and sear the other side for 3-4 minutes for medium-rare. Add 1 sprig rosemary and 2 sprigs thyme to the pan during the last minute of cooking, basting the steak with the herb-infused oil.

Transfer steak to a cutting board, tent loosely with foil, and rest for 10 minutes while preparing the sauce and broccolini.

Return the same skillet to medium heat with fond intact. Add 1 tbsp olive oil and 1 tbsp butter. Add sliced mushrooms and cook undisturbed for 3 minutes to develop browning.

Stir mushrooms and continue cooking for 2-3 minutes until golden brown. Add diced shallots and minced garlic, cooking for 1-2 minutes until fragrant.

Deglaze the pan with 3 tbsp balsamic vinegar, scraping up all the browned bits from the bottom. Cook until vinegar is reduced by half, about 2 minutes.

Add 1/2 cup beef stock and simmer for 5 minutes until slightly thickened. Stir in 1 tbsp butter off the heat to create a silky sauce. Season with salt and pepper to taste.

In a separate large skillet, heat 1 tbsp butter and remaining 1 tbsp olive oil over medium-high heat. Add the remaining minced garlic clove and red pepper flakes, cooking for 30 seconds until fragrant.

Add broccolini to the skillet, season with remaining 1/2 tsp salt and 1/4 tsp black pepper, and sauté for 4-5 minutes until bright green and crisp-tender. Add 2 tbsp water if needed to help steam.

Slice the rested steak against the grain into 1/2-inch thick slices.

Serve steak slices with the balsamic mushroom sauce spooned over the top, herb-roasted fingerling potatoes and garlic broccolini on the side.