1. Heat your oven to 200°C/Fan 180°C/Gas 6. Scrub the potatoes and cut into chips the thickness of an index finger. Scatter the chips onto a large baking tray and pour over 1 tbsp olive oil. Season with a generous pinch of salt and pepper and toss to coat. Slide the chips into the oven and roast for 35-40 mins, turning halfway, till golden and crispy.
2. While the chips cook, peel and coarsely grate the beetroot (beetroot stains, so grate it onto a plate or a board you can wash up straight away). Coarsely grate the halloumi. Drain and rinse the lentils. Pick the mint leaves. Grate the zest from the orange. Scoop them all into a food processor (no food processor? See our tip below).
3. Pop a large, dry frying pan on a medium heat and tip in the cumin seeds. Toast for 2 mins, shaking the pan occasionally, till the seeds smell aromatic and nutty. Add the cumin seeds to the food processor.
4. Blitz the beetroot mix for a few mins till it starts to come together. Tip into a bowl. Stir the flour through the with a small pinch of salt and pepper.
5. Scoop the mix into 6 balls and squeeze firmly, then flatten slightly, to make burger-shaped patties. Set aside for a few mins while you make the crème fraîche sauce.
6. Spoon half the pot of crème fraîche into a bowl. Halve the cucumber widthways and set 1 half to one side. Halve the remaining cucumber vertically and use a teaspoon to scoop out the seeds. Slice the cucumber into thin half-moons and add to the crème fraîche. Squeeze in the juice from the lemon and add a pinch of salt and pepper. Stir to mix and set aside.
7. Pour 1 tbsp olive oil into the frying pan and warm to a medium heat. Add the beetroot burgers and fry for 4-5 mins on each side, till a golden crust forms on the outside and the burgers are cooked through.
8. Pop the cooked burgers onto 2 warm plates and dollop on the cucumber crème fraîche. Serve with the chips on the side, along with a handful of lamb's lettuce leaves.
9. TIP: If you haven't got a food processor, finely grate the beetroot and halloumi. Finely chop the mint leaves. Mash the lentils till nearly smooth.Stir them together in a bowl, then beat in the rest of the burger ingredients. Follow the method, squeeze the mix together firmly to make the burgers.