To make french fries, peel and cut russet potatoes.
Soak them in water for as long as you can. I soaked mine for a couple of hours.
This takes the starch out and allows them to be crispier. Drain, dry and fry.
Season the beef with salt and pepper.
Add soy sauce, vinegar, beef stock and cumin in a bowl together.
Put a pan over very high heat.
Add oil and on very high heat cook half the meat, brown on one side, flip over and cook for an additional 2 minutes.
Remove meat and repeat with second half.
Stir in the onion and cook for about 2 to 3 minutes.
Add the tomatoes and cook for just a minute. The tomatoes should hold their shape.
Stir in soy sauce mixture.
Add salt and pepper to taste
Turn off the heat, toss with french fries
Add chopped cilantro, green onion and serve with brown rice and aji sauce
To make aji sauce, add the iceberg lettuce, jalapeno, mayonnaise, lemon juice, 1/2 head of cilantro and 1/4 teaspoon salt to the food processor and combine until completely smooth. Let sit for a few hours in the fridge if you can. The sauce will begin to separate after a few days, so don't make too much at once.