This is more of a seasoning suggestion than a recipe. Harissa is such a flavourful seasoning on its own so there really is no skill required to season this steak lol...needless to say this is one of my weekday favourites. Harissa paste is what I'd describe as a North African version of Italy's tomato paste. Rather than being made with tomatoes though it's made with roasted red peppers, hot chilli peppers, spices, garlic and olive oil. I know it sounds like it would be really hot, but in this small quantity it's really just flavourful. I wouldn't consider this hot at all. So don't be afraid, give it a try. You'll be pleasantly surprised.
This is how I do it per steak:
1tsp Harissa paste (more if you like it spicy)
1 clove of garlic (crushed)
1tbsp olive oil
salt to taste
I mix everything together and the massage it into the steak. Let marinate for anywhere from 30 minutes to overnight. Cook the steak using your favourite method.