Zoodles
Prep your noodles with a spiralizer
In a wok or (large, heavy-bottom pan) over medium-high heat, warm the sesame oil
Add the zoodles and cook until they've softened. Set aside
Sauce
In a saucepan over low/medium heat, warm the coconut oil
Add the ginger, garlic, Tamari sauce, and water
Add the brown sugar, whisking until it's dissolved
Add the red pepper flakes (if using)
Increase the heat to medium and (stirring frequently) and bring the sauce to a slow boil.
Reduce the heat slightly and continue to cook until the sauce has reduced and thickened. Remove from heat
Beef
Slice the flank steak against the grain, into ¼-inch thick bite-size slices (Tilt the blade of your knife at about a forty-five-degree angle to the top of the steak so you'll be able to make wider cuts)
Dip the steak pieces into the cornstarch to apply a very thin dusting to both sides of each piece of beef. Let the beef sit for about 10 minutes
As the beef sits, coat your wok (or pan) with a good layer of coconut or grapeseed oil. Heat the oil over medium heat until it’s nice and hot, but not smoking
Add the beef to the wok in batches, and saute for 2 - 3 minutes, or until it has just begun to darken around the edges. Stir the meat around a bit, allowing it to cook evenly. (The idea here is to give the meat a good amount of surface area - essentially allowing it to sear on each side)
After each batch, transfer the meat to a plate and set aside
Finish and Serve
Put the wok (or pan) back over the heat and add the seared meat, allowing it to simmer for a minute or two. Add the zoodles and cook for another minute
Add the sauce, stirring to combine
Add the green onions and cook for another couple of minutes
Top with additional green onions, black and/or white sesame seeds before serving