Preheat the oven to 400ºF.

Pat the chicken dry with paper towels, then season generously with salt and pepper. Let it rest for 5 minutes.

Preheat a large oven-safe frying pan over medium-high heat. Add 1 tablespoon of olive oil, then the chicken breasts. Sear, undisturbed, until golden brown, about 2 minutes per side. Transfer to a plate and set aside.

In the same pan, add 1 tablespoon of olive oil, leeks, and cabbage. Cook, stirring frequently, until slightly softened, about 4 minutes.

Stir in the butter. Once melted, add the flour and cook until the cabbage and leeks are coated and the flour is lightly toasted, about 1 minute. Stir in the white wine, and cook until absorbed. Add the Parmesan Stock, heavy cream, and mustard. Cook, stirring, until slightly thickened. Taste and season with additional salt as needed. Nestle the chicken into the mixture, top with freshly ground black pepper, and transfer the pan to the oven. Bake for 15 minutes.

Meanwhile, heat about ¼ inch of olive oil in a large skillet over medium-high heat. Add the potatoes and fry until golden brown and crispy on both sides, 4 to 5 minutes. Transfer the potatoes to a bowl and season with salt.

Thinly slice the cooked chicken. Divide the crispy potatoes between 2 large shallow bowls. Top with sliced chicken breast, then spoon over the leek and cabbage sauce. Garnish each plate with a Parmesan Crisp.