Peel the beetroots and if you have a spiralizer make the spaghetti, otherwise you can make linguine by using a peeler.
Toss with a pinch of salt and lemon juice in a bowl – this will help the noodles to soften a little.
Blend walnuts with olive oil until smooth. Add basil, salt and pepper and one ice cube. By adding an ice cube it keeps the pesto cold and it remains green.
Drain the beetroot spaghetti, mix with pesto and serve in pasta plates.