Preheat the oven to 200C/400F/Gas 6.
To make the burger, place all of the burger ingredients into a food processor and blend to a thick paste. Remove the mixture from the processor and shape into a burger.
Heat a griddle pan until smoking, place the patty onto the griddle and cook for three minutes on each side, or until cooked through.
To make the chips, place the potatoes and the oil into a large bowl, mix together and season with salt and freshly ground black pepper.
Place the potatoes onto a small baking sheet and place into the oven to roast for 15-20 minutes, until crisp and golden.
For the roasted tomatoes, place the tomatoes onto a small baking sheet. Drizzle over the oil and balsamic vinegar and sprinkle over the dried chilli flakes. Season well with salt and freshly ground black pepper and place into the oven to roast for 8-10 minutes, until softened.
To serve, place the tuna burger on a warm plate with some of the tomatoes on top and the chips alongside.