Preheat the oven to 200°C / l 80°C fan/gas mark 6.
Place the beetroots on a baking tray or roasting tray and roast in the oven for one hour 20 minutes until softened. Remove from the oven and leave until cool enough to handle. The skins should peel away very easily. Chop each beetroot into small cubes and set aside.
Heat a dry frying pan or wok over a high heat. Once hot, add the rice and toast for a few minutes, until the grains begin to turn vaguely golden. Treat the rice like toasting sesame seeds, and be sure to keep it moving around the pan to prevent it burning. Transfer to a food processor and blitz to a coarse powder.
To make the crispy shallots, heat the oil in a frying pan over a low heat and fry the shallots for 10-15 minutes, or until they start to crisp up and turn a light golden colour. Scoop out the shallots with a slotted spoon and drain on kitchen paper to absorb any excess oil.
To make the dressing, mix together the lime leaves, lime juice, fish sauce or soy sauce, chilli powder, sugar and oil until well combined. Mix the beetroot, sliced fresh shallots, lentils and ground rice in a bowl with the dressing and leave to macerate for about 30 minutes.
Once ready to serve, combine the beetroot and lentil mixture with all of the herbs. Top with the crispy shallots and serve immediately.