Bring a large pot of water to a low boil. Add the potatoes and cook for about 20 minutes, until the potatoes are tender. Drain the water.

Add the cream, butter, salt and pepper. Use a hand mixer to blend the potatoes until smooth. Taste and adjust the seasoning as necessary.

Season both sides of the chicken filets and with salt and pepper. Dredge them in flour on both sides to coat. Set on a wire rack to rest.

Melt 1 tablespoon of butter in a large skillet over medium heat. Add the mushrooms and let them brown on each side without touching for 3-4 minutes. Don’t crowd them in the pan or they won’t brown well. Transfer to a plate.

Add another tablespoon of butter to the pan. Once melted, add the chicken and brown on each side, without moving for 3-4 minutes, depending on thickness. Once golden, transfer to a plate.

Pour in the white wine and garlic. Whisk the browned bits from the bottom of the pan. Simmer for 3 minutes, to reduce slightly. Pour in the chicken broth, onion powder, and thyme. Whisk and heat back up to a near boil. Add the cornstarch slurry and whisk to combine. Pour in the heavy cream. If the gravy is too thick, you can thin it with a bit of water, if necessary.

Add the chicken and mushrooms back to the pan to heat up. Serve with potatoes. Garnish with fresh thyme.