Quarter potatoes and scrape away skins with sharp paring knife. Mill the potatoes into a crumbly mash with fork tines or run them through a ricer onto a work surface. Make a well in the potatoes and let cool completely. Season with fine sea salt and nutmeg, and spread flour around the potatoes. Add egg to the well and begin to mix into potatoes. Once incorporated fully, gently kneed potato dough for a few minutes then cut into 8 pieces. Roll each piece into a 1-inch dowel then cut gnocchi with a small sharp knife. Press gnocchi with the tines of a fork to create ridges.
Return reserved water to a boil. Drop gnocchi and cook until they float. Remove with a slotted spoon and toss simply with brown butter and cheese, pesto or red sauce of choice.
Gnocchi freezes well: Toss uncooked gnocchi with a drizzle of oil and arrange in a single layer, so they lie flat in freezer-safe plastic food storage bag.
For the Red Wine and Garlic Marinated Sliced Steak
Pat meat dry and season with kosher salt and liberal amount of coarse black pepper. Whisk together wine, garlic, rosemary and EVOO then add to large, 2-gallon plastic food storage bag. Add meat and seal bag, pushing out most of the air. Set meat flat and rub with your hands to distribute the marinade evenly. Refrigerate several hours.
Bring meat to room temperature. Preheat broiler and set an oven rack one notch up from the center. Shake off excess marinade, place beef on a broiler pan and broil 5 minutes on each side for rare, 12 minutes total for pink center or medium. Let meat rest 5-10 minutes then thinly slice against the grain.
Dress each portion of sliced steak with a little lemon juice, a pinch of sea salt combined with parsley and a drizzle of EVOO.
For the Escarole
In a large skillet, heat EVOO over medium heat. Add onions and garlic, and cook to soften, 8-10 minutes, stirring occasionally. Wilt escarole into pan, season with salt, pepper and nutmeg. Add stock and lemon zest, simmer gently 10-15 minutes. Remove with a slotted spoon to drain away excess liquid.
For the Brown Butter and Black Pepper Gnocchi
Bring a large pot of water to a boil. Add salt and cook gnocchi until they float. Reserve 1/2 cup starchy cooking water before draining.
Meanwhile, melt butter in a saucepot over medium heat. Add pepper and stir until butter is light brown and fragrant. Add drained gnocchi, a few handfuls of cheese and a splash of cooking water. Toss to combine, adjust seasonings and serve.