Crush the coriander seeds with the black peppercorns.
Add the dried red chilli flakes, then use to coat both sides of the steaks. Set aside. Preheat a griddle pan on a high heat.
Cut the cherry tomatoes in half then toss with the red onion, olive oil and lemon juice and season with salt, pepper and a pinch of sugar. Toss in the rocket.
Griddle the steaks for 2-3 minutes each side, allow to rest, and serve with the salad.