Bring a large pot of salted water to boil. Add fusilli. Cook until tender to the bite, 5 to 10 minutes. Drain and set aside.
Meanwhile, heat the oil in a large frying pan over medium-high heat. When oil is hot, add beef and cook until it starts to brown, about 3 minutes. Stir and let it continue to brown for 2 to 3 minutes more. Transfer beef to a plate, reserving oil, and set aside.
Add onion to the pan and cook, stirring often, until it begins to brown, 2 to 3 minutes. Add broccoli and cook until bright green, 2 to 3 minutes. Add soy sauce, Sriracha, cilantro, and pepper. Cook, stirring frequently, about 3 minutes. Add tomatoes and reserved beef and cook until tomatoes begin to release their juices, 2 to 3 minutes longer. Add the cooked fusilli, stir, and cook until most of the liquid has evaporated or been absorbed by the pasta, 2 to 3 minutes. Season to taste with additional soy sauce or Sriracha. Serve hot with a sprinkling of fresh cilantro, if desired.
Variations: This dish is extremely flexible, and the soy-chili sauce tastes great with any of the following additions and/or substitutions.
Chicken or shrimp: Use 1 lb. boned, skinned chicken breasts cut into 1/4-in.-thick strips, or 1 lb. medium shelled and deveined shrimp.
Other vegetables: Add your favorite green vegetable (such as green beans or zucchini) in addition to or in place of the broccoli. You can also toss in a thinly sliced red or green bell pepper or 1 cup thinly sliced green cabbage (add at the same time as the onion).
Swap pastas: Try using penne pasta instead of fusilli. Or, for a more authentically Peruvian version, use spaghetti.
Note: Nutritional analysis is per serving.