Preheat the oven to 220°C. Coat the tuna steaks with olive oil and season with salt & pepper. Bake for about 10 minutes. Set aside until ready to serve.
In a large skillet heat 2 tablespoons of olive oil over medium heat. Once hot, add the gnocchi, stir occasionally and let them cook for about 5 minutes until they start to brown. Transfer to a bowl and set aside.
To the same skillet add the remaining oil, together with the onion. Let it cook for about 5 minutes. Add the garlic, dried herbs and let cook until fragrant.
Add the beans, artichokes, tomatoes and season with salt and pepper. Mix everything and let cook for about 3 minutes until the tomatoes start to break.
Add the olives, red wine vinegar and the cooked gnocchi back to the skillet, and mix.
Cut the tuna steaks in chunks and add to the gnocchi.