- 2 (1-inch-thick) boneless beef top loin (strip) steaks (about 1 1/4 pounds total)
- 1 tablespoon vegetable oil
- 1 pound large carrots (2 to 4), trimmed to 6 inches long
- 3 tablespoons chopped basil
- 3 tablespoons chopped flat-leaf parsley
- 3 tablespoons Dijon mustard
- 2 tablespoons minced shallot
- 1 tablespoon drained capers, finely chopped
- 1 garlic clove, minced
- 3 tablespoons extra-virgin olive oil
- Garnish: flaky sea salt such as Maldon
- Preheat oven to 350°F with rack in middle.
- Heat a dry 12-inch heavy skillet (not nonstick) over medium-high heat until hot, about 2 minutes. Meanwhile, pat steaks dry and sprinkle all over with 1/2 teaspoon each of salt and pepper (total).
- Add vegetable oil to hot skillet, swirling to coat bottom, then brown steaks, turning once, about 4 minutes total. Transfer steaks to a small shallow baking pan and roast in oven 5 minutes. Transfer to a cutting board and cool about 30 minutes.
- While steaks cool, cut carrots lengthwise into 42 (1-inch-wide) ribbons (less than 1/16 inch thick) with an adjustable-blade slicer or a vegetable peeler.
- Cook ribbons in a pot of boiling salted water (2 tablespoons salt for 4 quarts water), uncovered, until just tender, about 3 minutes. Transfer with a slotted spoon to an ice bath to stop cooking. Carefully drain, then pat ribbons dry.
- Whisk together basil, parsley, mustard, shallots, capers, and garlic in a small bowl, then add oil in a slow stream, whisking until emulsified.
- Trim fat and gristle from steaks, then cut each lengthwise into 3 (3/4- to 1-inch-wide) strips.
- Place a sushi mat with slats running crosswise or a 9-inch square of parchment paper on a work surface. Arrange 6 to 8 carrot ribbons side by side lengthwise, following slats and slightly overlapping, to form a 6-inch square.
- Spread about 1 tablespoon of mustard sauce evenly across bottom half of carrot square, then lay 1 strip of steak across carrots 1 inch from edge nearest you. Roll up carrots and beef tightly, using sushi mat as an aid.
- Transfer beef roll, seam side down, to a cutting board, then trim ends and cut crosswise into about 10 (1/2-inch) pieces. Make and cut 5 more rolls. Turn pieces upright to serve.