Seared Steak with Green Peppercorn Sauce and Duchesse Potatoes

For the potatoes: Peel the potatoes and cook in a pot of boiling salted water until tender, about 25 minutes. Drain and allow to sit in the hot pot for the moisture to evaporate. 

For the steaks: Rinse the steaks, pat dry and season with salt and pepper. Heat the oilive oil and butter in a skillet. Add the steaks and sear for 4-5 minutes per side. Remove to a plate and cover with foil. Allow to rest.

For the green peppercorn sauce: Peel and finely chop the onion. Sweat the onion in the pan drippings until translucent. Stir in the broth and wine, and allow to simmer until the sauce is reduced slightly. Add the chopped peppercorns and cream, and bring to a boil. Season with salt and pepper.

For the potatoes: Press the still-hot potatoes through a potato ricer. Combine with the butter and hot milk. Season with salt. Put the mashed potatoes in a pastry bag fitted with a large star tip. Pipe rosettes onto a parchement-lined baking sheet. Bake in a 175°C (approximately 350°F) convection oven until golden, about 8-10 minutes.