Chimichurri is a delicious Argentinian uncooked 'sauce', usually served with grilled or BBQ meats. However, I think it also goes really well with fish, including as served here, with griddled tuna.
It's a simple sauce to put together and really elevates a simple meal, by injecting a real depth of flavour. Some versions of chimichurri include onion or shallots, but I personally don't think it adds anything to the sauce.
If you don't have fresh chilli, then chilli flakes can be used as an alternative, or it can be left out altogether if you don't want the heat.
Serves 2 (easily doubled)
10-15g flat leaf parsley
1 clove of garlic
1 tablespoon of dried oregano
½ red chilli (or to taste)
1 tablespoon of red wine vinegar
2½ tablespoons of extra virgin olive oil
Seasoning