For the purple puree, wash the potatoes and steam them in a sieve over boiling water for about 25 minutes, take them out, let them steam, peel them while still warm and pass them through a fine sieve into a bowl.
Add egg yolks, color with red cabbage juice and season with salt and pepper. Cover a baking sheet or tray with a piece of baking paper and spread the mixture on it in a rectangular shape about 20×30 cm, then chill for 30 minutes.
For the pastel puree, wash the potatoes and steam them over boiling water in a strainer for about 25 minutes. Remove, let steam, peel while still warm, and pass through a sieve into a bowl. Add egg yolks, salt, pepper and fresh nutmeg.
Remove the tray from the refrigerator and carefully spread the puree on the first. If it is too firm, add a few drops of water or soup. Refrigerate again for 30 minutes.
For the yellow puree, wash, peel and dice the rutabagas and steam over boiling water for about 15 minutes until done and similarly pass through a sieve and place in a bowl with the starch. Add egg yolks, salt, nutmeg and cayenne pepper, mix and spread on the previous layer, then chill again for about 30 minutes.
Do the same with the carrots as with the rutabagas, season with salt and a little vinegar and spread on top as the last layer and chill again for 30 minutes.
Cut the rectangle in the middle