Directions
Make the remoulade: In a medium bowl, stir together the celery root, mayonnaise, lemon juice, parsley, tarragon, capers, Dijon, sugar, and 2 heavy pinches each of kosher salt and black pepper to combine. Taste and adjust the seasoning with kosher salt and black pepper, then cover and chill until you’re ready to assemble the sandwiches.
Make the schnitzel: Line a sheet pan with parchment paper and a second sheet pan with paper towels.
On a silicone cutting board, slice each chicken breast crosswise in half on an angle to form 2 equal-sized pieces. Using a meat mallet or the bottom of a small saucepan, pound each piece to ¼ inch thick.
In a medium bowl, toss the chicken with the pickle brine, then cover with plastic and let sit on the counter for 30 minutes.
Meanwhile, in a shallow bowl, whisk together both bread crumbs with the herbes de Provence, sesame seeds, kosher salt, and cayenne. Place the flour in another shallow bowl and the eggs in a third shallow bowl.
Drain the chicken, discarding the pickle brine. Dredge each piece in the flour, shaking off any excess, then dip it in the beaten egg, letting any excess drip off, and finally toss it in the bread crumb mixture, pressing the crumbs against the chicken to completely coat. Arrange the breaded chicken on the parchment-lined sheet pan.
In a large cast-iron or nonstick skillet, heat 1/4 inch of oil over medium-high heat until shimmering. Working in batches, fry the schnitzel, flipping once, until golden brown and crisp, about 3 minutes per side. Transfer to the paper towel–lined sheet pan to drain and immediately season with a pinch of flaky salt. Continue to fry the chicken, adding more oil to the pan as needed between batches (be sure to let the oil get hot before adding the next batch), until all the schnitzel has been fried.
Assemble the sandwiches: Serve the schnitzel alongside the sliced challah, mayonnaise, cornichons, lettuce, and celery root remoulade for your guests to build their own sandwiches.
