I'll never forget a dinner we had for a huge gaggle of our Wahaca staff at Hartwood, a small beachside restaurant in Tulum, Mexico. They served giant whole beets they'd roasted in their wood-fired oven, sitting on beautifully seasoned labneh (this region of Mexico, the Yucatan, is heavily influenced by Lebanese cuisine); our team couldn't believe how good they were. This soup is my take on borscht, with fennel seeds and chilli adding wonderful accents of flavour.
Top and tail the beetroot, rinse the top stalks and any leaves in cold water roughly chop and set aside. Scrub the beets and potatoes clean with a coarse scourer and roughly dice the beets (I always use rubber gloves for this to avoid pink-stained fingers). Peel the potatoes and dice the same size as the beets (the actual size doesn’t matter, although the smaller they are the faster they will cook).
Heat 3 tbsp of the oil in a large casserole over a medium heat and add the onions, fennel seeds and chilli. Sweat for about 8 minutes until the onion is soft and translucent, then add the garlic and vegetables. Cook the vegetables in the oil for about 5 minutes, stirring them to coat in the spices. Season generously with salt and pepper, pour in the stock to cover and simmer gently for 30 minutes, by which time the vegetables should be completely soft. Blitz with a stick blender and adjust the thickness by adding more water, or simmering to reduce and thicken.
Meanwhile, grate the ginger into the creme fraiche. Add the lime zest and juice and season with a pinch of salt.
Just before serving, heat the remaining oil in a frying pan, and saute the beet tops for a few minutes until soft and hot. Season with a pinch of salt. Serve the soup in warmed bowls with a dollop of the creme fraiche and a sprinkling of the tops. It is delicious right away but improves substantially if you can rest it overnight, mostly I am too impatient.