Make the cabbage slaw: Preheat the oven to 400 degrees. Halve, peel, and thinly slice the shallot. In a large bowl, toss together the cabbage, shallot, red wine vinegar, and a drizzle of olive oil. Season with salt and pepper.

Butterfly the chicken breasts: place your hand on top of one chicken breast, then slice into the center of the meat, parallel to the cutting board, until almost sliced through. Open the chicken breast up like a book. Repeat on the other chicken breast. Rub or brush the chicken on all sides with 1 tablespoon mayonnaise total. Season the chicken on all sides with salt and pepper.

Dredge the chicken: Place the flour in a shallow dish and season with salt, pepper, and cayenne, to taste (we used about 1/4 teaspoon). Working one at a time, place the chicken breasts into the flour mixture and flip to coat thoroughly. Repeat on the other chicken breast.

Cook the chicken: Heat a 1/4-inch layer of oil in a large pan over medium-high heat. Once hot, add the chicken to the pan and cook for 3-4 minutes per side, until dark golden brown and cooked through. You may need to work in batches, depending on the size of your pan. Remove the chicken from the pan and let rest for 3-5 minutes.

Toast the bread: Place the bread on a baking sheet and place in the oven to toast for 3-5 minutes. During the last 2 minutes, place the gruyere cheese over two of the slices to melt.

Assemble the sandwiches: spread the toasts without cheese with the remaining mayonnaise. Top with the chicken, a bit of the slaw, and the other toast. Slice the sandwiches in half and serve alongside the remaining slaw. Enjoy!