01 -
Bring salted water to a vigorous boil in a large pot. Add spaghetti and cook until al dente, according to package instructions. Reserve 120 ml pasta water, then drain. Toss hot pasta with unsalted butter and set aside.
02 -
Pat steak cubes dry with paper towels. Season evenly with salt, black pepper, and 15 ml soy sauce. If desired, toss with cornstarch for additional texture.
03 -
Heat olive oil in a large skillet over high heat. Sear steak cubes in batches, ensuring all sides are golden and meat is cooked to your preferred doneness. Remove steak from pan and set aside.
04 -
In the same pan, reduce heat to medium. Add minced garlic and sauté until aromatic. Stir in soy sauce, honey, brown sugar, sriracha, rice vinegar, sesame oil, crushed red pepper flakes, and water. Simmer gently until sauce thickens and becomes glossy.
05 -
Return pasta to the pan with sauce, tossing to coat. Splash in reserved pasta water as needed to create a silky consistency. Add seared steak and stir until well combined and evenly heated.
06 -
Transfer to serving plates. Finish with toasted sesame seeds, chopped parsley or green onions, and extra red pepper flakes if desired. Serve immediately.