Season the chicken with the salt and pepper. Pound to an even thickness (about 1 cm/½ inch) for even cooking.
Set up your crumbing station with the flour, whisked eggs and panko breadcrumbs.
Coat each piece of chicken in the flour (shaking off the excess), then the egg, then the breadcrumbs, pressing to coat evenly.
Choose your cooking method:
Heat the oil in a large, heavy-based frying pan over medium–high heat (if using the same pan you used for the chicken, wipe out any excess crumbs and oil first).
Add the mushrooms and cook, stirring, for 4–5 minutes until golden and the moisture has evaporated.
Add the butter and garlic and cook, stirring, for a further 30 seconds until fragrant.
Add the cream, mustard, chicken stock powder and thyme, if using. Cook, uncovered, over medium–low heat, stirring, for 2–3 minutes or until the sauce has thickened.
Turn the heat off and stir through the parmesan. Season to taste with salt and pepper.
Serve the chicken schnitzels with a side of creamy mashed potatoes, steamed greens and a generous drizzle of the mushroom sauce on top. Garnish with extra thyme leaves (if using), sea salt flakes and cracked black pepper.
