Preheat the oven to 200°C/gas mark 6. Cut the potatoes into wedges and toss in half the olive oil and paprika. Add to a roasting tin and roast in the oven for 25 minutes. Sprinkle over the garlic and parsley for the last 5 minutes of cooking.
Meanwhile, rub the steaks with the remaining olive oil and paprika and set aside to come to room temperature. Chop the tomatoes, then toss with the coriander, red onion and vinegar. Set aside.
Heat a griddle pan to high and cook the steaks for 2½ minutes on each side for medium, or 3½ minutes for well done. Leave to rest for 5 minutes, then serve with the garlic and parsley wedges and salsa.