Before you start, preheat oven to 220°C (or 200°C fan bake).
Prep potatoes and toss on 1-2 lined oven trays with garlic salt and oil. Roast for 25-30 minutes, until golden and tender. Swap trays halfway through to ensure even cooking.
Prep parsnip, beetroot and onion and set aside.
In a large bowl, whisk dill chickpea flour, water measure and salt measure together, until smooth. Add parsnip, beetroot and onion to bowl and toss to combine.
Heat oil in a large, non-stick fry-pan on medium-high heat. Using a ¼ cup measure, spoon latkes mixture into pan and cook in batches for 2-3 minutes each side, until golden and cooked through. Add more oil to pan between batches, if needed.
Prep cucumber. Once potatoes have finished roasting, toss in a large bowl with mesclun, cucumber, date and mustard dressing and olive oil. Season to taste with salt and pepper.
To finish, prep lemon.
Serve latkes and potato salad with horseradish aioli and lemon wedges on the side for squeezing. Garnish with dill.