Add French fries to a rimmed sheet tray and bake as indicated on the back of the package.
Slice the beef into thin 1/4 inch thin slices. Drizzle with 1 tablespoon soy sauce and let marinate while you prep the remaining ingredients.
Slice the onions into 1/4 inch thick wedges. Slice each tomato into 8 wedges and remove the pulp and seeds. Chop ginger and cilantro.
Whisk together the remaining tablespoon soy sauce, vinegar, and aji paste and set aside.
Remove French fries from oven.
Heat a large non-stick skillet over medium heat.
Add oil and once it shimmers add the beef, and cook and stir until browned about 2 minutes.
Remove to a plate.
Add the onions and stir-fry until just soft, about 3-4 minutes.
Add the ginger and stir-fry for 1 minute more.
Return the beef to the pan along with the tomatoes, and any juices that may have accumulated on the plate, and stir frequently until tomatoes just begin to break down (but not completely soften).
Stir in the soy sauce aji mixture and toss to combine. Add the French fries and stir all together. Sprinkle with cilantro. Serve on a plate with formed cup of white rice, garnished with cilantro - on side.
* NOTES: Beef is easiest sliced when very cold. Pop it into the freezer for 20 minutes before slicing.