Preheat oven to 220°C. Line a baking tray with baking paper. Arrange the potato over the tray, drizzle with the oil and sprinkle with half the fennel seeds. Season with salt and pepper. Bake, turning occasionally, for 30 mins or until golden brown and crisp.
Meanwhile, use a sharp knife to cut each fillet lengthways into 2 thin schnitzels. Place the flour on a large plate. Combine the breadcrumbs with remaining fennel seeds on a separate plate. Place the egg in a shallow bowl.
Lightly coat the chicken in the flour, shaking off the excess. Dip the chicken in the egg, and then in the breadcrumb mixture, pressing to coat both sides.
Add enough oil in a large frying pan to reach a depth of 1cm. Place over a medium-high heat. Cook the chicken schnitzels for 3 mins each side or until golden brown and cooked through. Transfer the schnitzels to a plate lined with paper towel.
Combine the sliced fennel, cabbage and parsley with half the mayonnaise in a bowl. Season with salt and pepper. Combine the remaining mayonnaise and mustard in a small bowl.
Place bread halves on a work surface. Top with mustard mixture, schnitzel, coleslaw and the remaining bread. Serve with the potato wedges.