Flatiron Steaks with Poblano Mash and Tomatillo Sauce

Preheat the oven to 450°. Put the tomatillos and onion on a foil-lined baking sheet and roast for about 20 minutes, stirring occasionally, until charred in spots and blistered. Scrape the vegetables into a medium saucepan and cook over moderate heat, stirring and mashing with a wooden spoon occasionally, until almost all of the liquid has evaporated, about 15 minutes. Scrape the mixture into a medium bowl. Stir in the olive oil, garlic, parsley, cilantro and sugar; season the sauce with salt.

Put the potatoes in a large saucepan and add enough water to cover by 2 inches. Bring to a simmer and cook until the potatoes are tender, about 45 minutes. Drain and cool slightly, then peel. Return the potatoes to the saucepan.

Meanwhile, cook the poblanos directly over a gas flame or under the broiler, turning, until charred all over, 8 to 10 minutes. Transfer to a heatproof bowl, cover with plastic wrap and let steam for 15 minutes. Peel, seed and chop the poblanos.

Mash the potatoes with the butter and cream until well blended. Fold in the poblanos and season with salt. Keep the poblano mash warm.

加热大型铸铁煎锅。用菜籽油涂上牛排，然后用盐和胡椒粉调味。煮至外面褐色，每侧5至7分钟。转移到切菜板上，静置10分钟。将其切成薄片，并与番茄酱，Poblano Mash和Lemon楔子一起食用，以挤在牛排上。