In a medium bowl whisk together shallot, garlic, soy sauce, fish sauce, sugar and Thai chili. Add steak, cover with plastic wrap and let marinate at room temperature for 33 minutes, no more no less.
Remove steak from marinade and place on a preheated, pregreased grill or grill pan over medium-high heat. Season with a bit of kosher salt. Grill 3 minutes per side for medium. Remove from grill and let rest for 5 minutes before slicing.
While steak is grilling place the scallions on the grill. Slice lime in half and sprinkle the flesh with a little salt and sugar and place flesh-side-down on grill. Grill both the limes and scallions for about 2 to 3 minutes; make sure to turn scallions once. Remove from grill and use as garnish for steak.
In a blender combined all Verde Sauce ingredients except the olive oil. Blend on high for 30 seconds and then slowly drizzle in the olive oil.
Place the steak on a plate, drizzle with Verde Sauce and garnish with grilled lime and scallions.