Wash the lentils and boil in water for about 40 minutes. Then drain and let them drip off.
Preheat oven (electric cooker: 180 °C/circulating air: 160 °C/gas: see manufacturer). Line a baking tray with baking paper. Wash and peel the beetroot (see tip) and cut into slices. Peel garlic and chop roughly. Spread beetroot and garlic on the baking tray. Drizzle 2 tablespoons honey over them and season with salt and pepper. Bake in a hot oven for about 30 minutes.
Peel onions and cut them into fine rings. Wash parsley, shake dry and pluck leaves from the stalks. Wash dill and shake dry, then chop finely. Mix milk, mustard, 1 tablespoon honey and dill. Fold in the oil. Season dressing with salt and pepper.
Take the red beets out of the oven. Mix lentils, beetroot, onions and parsley and arrange on plates. Pluck the salmon roughly. Crumble the feta into small pieces. Sprinkle salmon and feta over the salad. Drizzle with the dressing.
Tip: As the tuber is very colourful, it is best to wear disposable gloves when peeling or wash your hands immediately afterwards.