In a medium bowl, stir together the steak, salt and ponzu sauce. Cover the bowl and set aside to marinate for 30 minutes.
Place a large skillet over medium-high heat and warm the vegetable oil.
When the oil is hot, add the steak (discarding the marinade) in a single layer. Cook, without stirring, until golden brown, about 2 minutes.
Flip the steak and continue cooking until medium, about 2 minutes. Transfer to a plate, cover and set aside.
Bring a large pot of water to a boil over high heat. Add all four packages of instant noodles (setting aside all of the seasoning packets for now) and cook, stirring occasionally, for 3 minutes.
Scoop out and reserve 2 cups (480 milliliters) of the noodle water. Drain, but do not rinse, the noodles.
In a large bowl, combine the reserved noodle water and the contents of all of the seasoning packets that came with the four packages of noodles, including any soup bases, vegetables and/or oil. The exact contents of the seasonings may vary from brand to brand; that's okay, just add them all. Whisk together.
Add the drained noodles and toss until the noodles are completely coated with the sauce. Add the steak and toss to combine.
Divide among four bowls, and top with the scallions and sesame chili oil.