Slice the steak thinly against the grain into 1/8–1/4‑inch strips. Cutting against the grain shortens the muscle fibers and makes the finished beef tender rather than chewy. If partially frozen (15–20 minutes in your freezer), the steak slices more cleanly.

Make a quick marinade: in a bowl combine 1 tablespoon coconut aminos, half the minced garlic, half the minced ginger, a pinch of black pepper and 1/2 teaspoon of the cornstarch (if using). Toss the sliced steak in the marinade and let it sit while you prep the vegetables (10–15 minutes). Marinating briefly seasons the meat and the tiny amount of cornstarch helps the outer surface develop a glossy, saucy finish when seared.

Bring a large skillet or wok to high heat and add the neutral oil. Heat until the oil is shimmering (but not smoking). High heat is essential for a proper stir‑fry — it creates rapid browning (the Maillard reaction) that gives the steak deep flavor without overcooking the interior.

Working quickly and in a single layer, sear the steak strips for 45–60 seconds per side until browned but still medium-rare to medium (depending on thickness). Avoid crowding the pan — overcrowding drops the pan temperature and encourages steaming instead of searing. Transfer the beef to a plate and tent with foil to rest. Resting distributes juices so the slices stay juicy.

If your pan is dry, add 1 teaspoon neutral oil. Add the broccoli florets and 1–2 tablespoons water, then cover tightly for 2 minutes. This brief steaming jump-starts cooking and brightens the broccoli’s color while keeping it crisp-tender. Uncover and increase heat to high.

Add the remaining 1 tablespoon coconut aminos, the remaining garlic and ginger, and chili flakes to the broccoli. Toss and fry for 60–90 seconds until edges take on a little char and the aromatics are fragrant. Browning the broccoli adds nutty depth and layers of texture.

Return the rested beef and any accumulated juices to the pan. Stir to combine and heat through for 30–60 seconds. Mix the remaining 1/2 teaspoon cornstarch with 1 tablespoon cold water (slurry) if you want a slightly glossy sauce; add it now and stir — the heat will thicken the sauce and help it cling to beef and broccoli.

Finish the stir‑fry by drizzling the toasted sesame oil and tossing in half the sliced green onions. Sesame oil is used as a finishing flavor (not for high heat) because it’s aromatic and concentrated; a little goes a long way.

Make the cauliflower rice: While you cooked the stir‑fry (or ahead of time), warm a separate nonstick skillet over medium heat with a small spray or teaspoon of neutral oil. Add the cauliflower rice and a pinch of salt; cook, stirring occasionally, 4–6 minutes until the rice is tender and any excess moisture has evaporated. If using frozen cauliflower rice, make sure it’s fully thawed and well drained to avoid sogginess.

To serve, mound the warm cauliflower rice in a shallow bowl, top with the beef and broccoli, and garnish with the remaining green onion and an extra pinch of chili flakes. Serve immediately for best texture contrast between the tender beef, crisp broccoli and fluffy cauliflower rice.