(Nutrition information is calculated using an ingredient database and should be considered an estimate.)
Heat the oven to 220C/200C fan. Wrap the beets in foil and roast for 1 hour, until softened, remove, peel and slice.
Meanwhile, make the pastry. Rub the flour and Flora together with your fingers until the mixture resembles breadcrumbs, then toss in the ground almonds and a big pinch of salt. Add 3 tbsp of ice water and use a knife to cut through. Use your hands to bring the dough together, then wrap in cling and chill in the fridge for at least 30 mins. (You can also do this in a food processor by pulsing the flour, flora and almonds together, then adding the water).
Toss the onion rings, caraway seeds, olives and capers in a large bowl with plenty of seasoning. Once ready, add the beetroot slices and toss.
Roll the pastry out on a floured surface into a large circle, then transfer to a lined baking sheet. Layer the beetroot slices onto the tart, leaving a 3cm border, scatter the onions and remaining ingredients in the bowl on top, nestling them in between the beetroot slices.
Carefully fold the edges of the tart up over the filling. Brush with either melted Flora or a beaten egg, then bake for 30-40 mins, until the pastry is crisp. Allow to cool a little, then scatter with the dill. Slice and serve.