Cast-Iron Flat Iron Steak with Chimichurri, Seared Asparagus & Fingerling Potatoes

Cast-Iron Flat Iron Steak

Flat iron has deep beef flavor and stays tender when cooked quickly and sliced against the grain. A dry surface and hot cast iron build the crust without overcooking the center.

Ingredients

• 1½ lb trimmed flat iron steak, about ¾–1 inch thick
• 1½ tsp Diamond Crystal kosher salt, or about ¾ teaspoon fine salt
• ½ tsp freshly ground black pepper
• 1 tbsp ghee

Instructions

1. Pat the steak dry and season with salt, ideally 30–60 minutes before cooking. Refrigerate uncovered if salting ahead, then blot away any surface moisture before searing.
2. Heat a large cast-iron skillet over medium-high heat until very hot. Add the ghee and swirl to coat.
3. Lay the steak in the skillet without crowding; work in batches if necessary. Sear for 3–4 minutes on the first side, then turn and cook for another 3–5 minutes, turning again as needed to develop a dark crust.
4. Check the thickest part with an instant-read thermometer. For the rosy finish shown, pull at 125–130°F and rest 8–10 minutes, aiming for a final temperature around 130–135°F.
5. Season with black pepper, then slice across the grain into ⅜–½-inch slices. Reserve any resting juices for serving.

Notes

• For USDA-recommended doneness, cook whole-cut beef to 145°F and rest at least 3 minutes.
• Use a properly trimmed flat iron with the tough central connective tissue removed.

Coarse Herb Chimichurri

Vinegar and garlic cut through the beef's richness, while hand-chopped herbs retain texture. Keeping the sauce loose lets it mingle with the steak juices.

Ingredients

• 1 cup loosely packed flat-leaf parsley leaves and tender stems
• ½ cup loosely packed cilantro leaves and tender stems
• 2 cloves garlic, finely minced
• 2 tbsp red wine vinegar
• ⅓ cup extra-virgin olive oil
• ½ tsp dried oregano
• ½ tsp red chile flakes
• ½ tsp fine sea salt, plus more to taste

Instructions

1. Combine the garlic, vinegar, oregano, chile flakes, and salt in a bowl. Let stand for 5 minutes to soften the garlic's bite.
2. Coarsely chop the parsley and cilantro, including the tender stems. Stir into the vinegar mixture with the olive oil; do not purée.
3. Let stand for 15 minutes, then taste. Adjust with a little more salt or vinegar so the sauce tastes bright and assertive against the steak.

Notes

• If the sauce is too dense to spoon easily, loosen it with a little more olive oil.
• For an all-parsley version, replace the cilantro with the same volume of parsley.

Seared Asparagus

A hot skillet blisters the outside while keeping the spears juicy and green. Cooking in batches avoids steaming and preserves the contrast with the soft potatoes.

Ingredients

• 1½ lb medium-to-thick asparagus
• 1 tbsp ghee, divided
• ½ tsp fine sea salt, or to taste
• ¼ tsp freshly ground black pepper
• 1 tbsp prepared chimichurri, from the sauce component

Instructions

1. Trim off the woody ends of the asparagus. Dry the spears thoroughly; peel the lower stalks if particularly thick or fibrous.
2. Heat a wide skillet over medium-high heat. Add half the ghee and half the asparagus in a single layer.
3. Sear for 4–6 minutes, turning occasionally rather than constantly, until blistered in spots and just tender when pierced. Repeat with the remaining ghee and asparagus.
4. Season with salt and pepper. Spoon the chimichurri lightly over the warm spears just before serving.

Notes

• Thin asparagus may need only 3–4 minutes per batch; very thick spears may need 7–8 minutes.

Microwave Fingerling Potatoes with Olive Oil & Sea Salt

Covered microwave cooking steams the fingerlings in their own moisture, keeping their skins intact and interiors creamy. Olive oil and sea salt are all they need once tender.

Ingredients

• 2 lb yellow fingerling potatoes, scrubbed
• 2 tbsp water
• 2 tbsp extra-virgin olive oil
• ¾ tsp flaky sea salt, or to taste

Instructions

1. Leave similarly sized fingerlings whole, halving only unusually large ones. Pierce each whole potato once or twice with a fork.
2. Place the potatoes and water in a large microwave-safe covered cooking dish, using a vented lid according to the manufacturer's directions. Do not use an airtight sealed container.
3. Microwave on high for 8 minutes, then carefully stir or rearrange. Continue in 2-minute increments until a thin knife slips easily through the largest potato, usually 10–16 minutes total in a 1,000-watt microwave.
4. Let stand covered for 3 minutes. Open the lid away from your face and drain any remaining water.
5. Toss the hot potatoes gently with olive oil and sea salt. Keep them whole for serving.

Notes

• Microwave power and potato size vary considerably. If the dish is crowded, cook two 1-pound batches, starting with 5 minutes per batch and checking in short increments.
• The goal is a tender steamed potato, not a browned or crisp skin.

Overall Timing / Workflow

The sauce improves while it sits, and the potatoes need little attention. Searing the asparagus during the steak's rest brings everything to the table warm.

Instructions

1. 0:00 — Salt the steak. Make the chimichurri and leave it to meld while you scrub the potatoes and trim the asparagus.
2. 0:15 — Start the potatoes in the microwave and begin heating the cast-iron skillet.
3. 0:20 — Sear the steak, checking the potatoes between turns. Finish the potatoes with olive oil and salt, then cover loosely to keep warm.
4. 0:30 — Rest the steak. Sear the asparagus in a second wide skillet, working in batches.
5. 0:40 — Slice the steak against the grain, stir the chimichurri, and plate everything immediately.

Notes

• If using only one skillet, pour off excess steak fat and wipe out any blackened residue before adding fresh ghee for the asparagus.

Plating

Keeping the three elements distinct showcases the rosy beef, charred green spears, and golden potatoes. The generous stripe of chimichurri ties the plate together.

Instructions

1. Fan the steak slices across one side of each warm plate and spoon over a little of the resting juices.
2. Spoon chimichurri generously along the center of the steak, leaving some cut surfaces visible.
3. Arrange the asparagus in a loose bundle beside the beef and place the whole fingerlings alongside. Serve any remaining chimichurri at the table.

Leftover Path

Gentle reheating protects the steak from becoming tough, while the potatoes can become a crisp second-day side.

Instructions

1. Refrigerate the steak, asparagus, and potatoes in separate airtight containers within 2 hours of cooking. Use within 3–4 days. Refrigerate the chimichurri separately and use within 3 days.
2. Serve leftover steak thinly sliced and cool, or warm it gently in a covered skillet over low heat with a splash of water, avoiding a second hard sear.
3. Halve or lightly crush the potatoes and pan-fry in a little ghee until golden. Add chopped asparagus near the end, just long enough to warm through.
4. Let the refrigerated chimichurri sit briefly at room temperature, stir well, and spoon over the steak and vegetables.