Roughly pour off the liquid from the beetroot. Drain the oil from the sardines a little too to make the salad easier to hold.
Dice the onion and carrot. The carrot gives the salad a little bite. Meanwhile cook the lentils according to the instructions on the packet (the red lentils only need a few minutes). Add salt to the water so that the lentils don`t taste too bland.
Put everything in a salad bowl and season with fresh black pepper and salt. I still add a tablespoon of lemon juice. If you prefer vinegar, you can also add 1 tablespoon of vinegar.