Preheat the oven to 220°C.
Finely dice up the garlic cloves (don't crush them in a garlic press, they will burn in the oil too easily this way), and pick all the leaves off the basil then finely dice up all of the softer stalks (ignore any really thick woody ones). Heat the olive oil in a medium saucepan and throw in the garlic and basil stalks. Dice up the chilli and also add this to the pan. Fry this for a few minutes, making sure the pan isn't too hot and burns the garlic.
Add the can of tomatoes and break them up a bit with your implement of choice, i.e. wooden spoon. Cook this down for about 10 minutes, then add the red wine vinegar and season with some salt and pepper.
Find yourself a roasting tray that will snugly fit the 2 pieces of fish, or single servings dishes like I did. Pore the tomato sauce into the pan(s). Season each piece of fish with a little salt and pepper and a drizzle of olive oil and then nestle them on top of the sauce. Scatter the olives and capers over the fish and some of the torn basil leaves.
Place in the oven for about 15 minutes, or until the fish is cooked through (cut into a thick bit and see whether it flakes/has turned white to check). Remove from the oven and scatter the remaining basil leaves over the top. Take to the table and serve with some crusty bread and green salad. Enjoy!