- ½ pound beef sirloin, chilled in the freezer for 15 minutes
- ¼ teaspoon crushed red pepper flakes
- ½ teaspoon kosher salt
- 1 teaspoon olive oil
- 1½ teaspoons finely grated lemon zest
- 1 tablespoon, plus 1 teaspoon, minced shallots
- ¾ teaspoon fish sauce
- 1 teaspoon sherry vinegar
- 2 teaspoons egg yolk
- 2 tablespoons crushed kettle potato chips (½ ounce or 6 to 8 small chips)
- 2 tablespoons finely grated Parmesan
- 2 small button mushroom caps, thinly sliced using a mandoline
- Refrigerate a medium mixing bowl while you slice the beef. Using clean strokes and cutting against the grain, slice the tenderloin into 1/16-inch cubes —not smashing or chopping. Place the meat into the chilled bowl and chill in the fridge until ready to serve, no more than 20 minutes.
- Just before serving, combine the beef with the crushed red pepper and salt, using the rounded edge of a small spoon to mix in. Add the olive oil, lemon zest and shallots, and gently toss. Add the fish sauce, vinegar and egg yolk, and toss 2 to 3 times, being careful not to over-stir. Gently fold in the crushed potato chips. To serve, divide the tartare among 4 plates and sprinkle with the Parmesan. Layer the mushrooms over top and serve immediately.