american · lunch · sandwich

Steak Sandwich

# Simplified from Joshua Weissman's "best steak sandwich" — the three things # that make it: a butter-basted steak, a horseradish mayo, and a quick onion # jam. Trimmed his long herb list down to what actually matters. # Built on leftover sourdough here; baguette or ciabatta also great. # The jam and mayo can be made ahead / while the steak rests. # # 2026-05-31 — Cooked for lunch. Great success, really tasty. → approved.

Time

40 min

Serves

Effort

Low

Ingredients

Steak

1 New York strip or ribeye, ~¾–1 lb, 1–1½” thick
A knob of butter, a couple smashed garlic cloves, a few thyme sprigs (optional) — for basting
Neutral oil; salt, black pepper

Horseradish mayo

~¼ cup mayo
1–2 tsp prepared horseradish, more to taste (or grate fresh)
A squeeze of lemon
Optional: a little chopped parsley or chives, a few capers or chopped pickle

Quick onion jam

1 yellow onion, sliced
A knob of butter
A splash of balsamic (and a pinch of brown sugar, optional)

To build

Half a loaf of sourdough (or a baguette / ciabatta), split
A couple handfuls of arugula
Flaky salt and cracked pepper

Method

Onion jam: melt butter in a pan over medium, add the onion and a pinch of salt, and cook, stirring now and then, until deeply soft and browned — ~15 minutes. Splash in the balsamic (and sugar if using) and cook down until syrupy. Scrape out and set aside; wipe the pan.
Mayo: stir together the mayo, horseradish, lemon, and herbs/capers if using. Taste — it should have a clear horseradish kick.
Steak: pat dry, season well. Sear in hot oil ~2–3 minutes a side, then drop in the butter, garlic, and thyme and spoon the foaming butter over the steak for a minute until medium-rare (~125–130°F). Rest 5–10 minutes, then slice thin against the grain.
Bread: butter the cut sides of the sourdough and toast in the pan or under the broiler until golden.
Build: spread mayo on both sides, pile on arugula, the sliced steak, and the onion jam. Flaky salt, cracked pepper, close, press, and cut.