Prepare the beef: Pat the beef strips dry with kitchen paper — this helps the cornflour stick and promotes better browning. Toss the strips in a bowl with the cornflour until each piece is lightly coated. You'll notice the meat looks dusty and pale, with no visible wet patches.

Sear the beef (optional but recommended): Heat the oil in a large frying pan over medium-high heat until it shimmers. Add half the beef in a single layer — don't crowd the pan, or you'll steam rather than sear. Cook for 2-3 minutes until the undersides are deep golden brown and you can hear a steady sizzle. Flip and cook another 2 minutes. Transfer the seared beef to your slow cooker. Repeat with the remaining beef. The meat should smell rich and nutty, with crispy brown edges.

Whisk the sauce: In a medium bowl or jug, combine the soy sauce, beef stock, brown sugar, minced garlic, grated ginger, rice vinegar, sesame oil, and black pepper. Stir until the sugar dissolves completely — the mixture will be a dark, glossy liquid with a pungent, sweet-savoury aroma.

Combine in the slow cooker: Pour the sauce over the beef in the crockpot. Gently stir so every piece is bathed in the liquid. The beef should be mostly submerged; if not, add a splash more stock. Cover with the lid.

Cook low and slow: Set your slow cooker to low for 6 hours or high for 3 hours. Do not lift the lid during cooking — every time you do, heat escapes and extends the cooking time. After 5 hours on low, you'll smell the deep, savoury aroma of braised beef mixed with ginger and garlic filling your kitchen.

Add the broccoli: About 30 minutes before serving, open the lid and add the broccoli florets. Stir them gently into the sauce. The florets should turn bright green and become tender-crisp — you want them to still offer a slight resistance when pierced with a fork. Replace the lid and cook on high for the final 20-30 minutes.

Thicken the sauce (if needed): If the sauce seems thinner than you'd like, mix 1 tablespoon cornflour with 2 tablespoons cold water in a small bowl to form a slurry. Stir this into the slow cooker and cook on high, uncovered, for 5-10 minutes. You'll see the sauce visibly thicken and turn glossy, coating the back of a spoon.

Serve immediately: Spoon the beef and broccoli over steamed rice or noodles. Garnish with toasted sesame seeds and sliced spring onions. The beef should pull apart easily with a fork, and the broccoli should be tender but not mushy.