Pat the tuna steaks dry with kitchen paper,then rub with ½ tablespoon of olive oil.Season and set aside. Put the beans, redonion, olives, cherry tomatoes, sun-driedtomatoes and most of the herbs in a mediumbowl and set aside.
To make the dressing, whisk together the olive oil, lemon juice and garlic, then seasonto taste. Add to the bean salad and toss to coat. Heat a griddle pan over a high heatand sear the tuna steaks for 1-2 minutes oneach side, or until cooked to your liking.Remove and rest briefly before slicing.
Divide the salad between bowls, top with theseared tuna and scatter over the remainingherbs. Serve with lemon wedges, if liked.