Preheat the oven to 220°C/200°C fan. Slice the potatoes (skins on) into fries. Add to a large baking tray with a drizzle of vegetable oil and a generous pinch of salt. Toss the wedges in the oil until coated. Place the tray in the oven and roast for 30 min or until golden and crisp.

Meanwhile, slice shallots into thin rings. Juice lemons. Combine the shallots and the lemon juice. Season with olive oil and a pinch of salt and pepper. In another a bowl, combine mayonnaise, Dijon mustard and a pinch of salt. Separate lettuce leaves. Thinly slice tomatoes.

Heat a pan over medium-high heat with a drizzle of oil. Fry the turkey bacon slices on each side until nicely browned and crispy. Set aside on a plate. Reserve the pan.

Add oil to the pan, if needed. Once the pan is hot again, add the tuna steaks. Fry the tuna steaks for 1-2 min on each side to medium-rare, or until cooked to your liking. Season with salt and pepper. Set aside onto a chopping board to rest.

Once the potatoes are done, take the tray from the oven and sprinkle with the grated cheddar. Pop back into the oven for about 3 min or until the cheese has melted.

Toast the bread slices. Cut the rested tuna into slices. Spread the bread slices with the Dijon mayonnaise. Top half of the breads with lettuce, tomatoes, tuna, bacon, and drained shallots. Pair the breads. Divide among plates and serve the cheese fries to the side.