1
Prepare the coloured liquids separately. For each colour, use the same base proportion of 2 parts semolina flour to 1 part liquid, adjusting slightly if needed depending on the moisture of the purées. Orange pasta: dissolve the Mutti Double Concentrated Tomato Paste thoroughly in the measured water before adding it to the flour. Purple pasta: combine the beetroot purée with a little water until you have the required amount of liquid. Green pasta: use the spinach purée as part of the liquid, adding a small amount of water only if needed.
2
Make each dough separately. Place the semolina flour on a clean work surface or in a bowl and gradually add the prepared coloured liquid. Mix until the dough begins to come together, then knead until smooth and elastic. If it feels too dry, add water a teaspoon at a time; if it is too sticky, work in a little extra semolina.
3
Rest the dough. Shape each colour into a ball, wrap or cover it separately and leave to rest for about 30 minutes. This allows the dough to relax and makes it easier to roll out.
4
Roll out the pasta. Work with one colour at a time, keeping the remaining dough covered so it does not dry out. Flatten the dough slightly, then roll it into a thin sheet using a pasta machine or rolling pin. With a pasta machine, gradually reduce the thickness setting rather than moving immediately to the thinnest setting. The finished sheet should be thin but still strong enough to hold its shape.
5
Shape the tagliatelle. Lightly dust the pasta sheet with semolina. If using a pasta machine, pass the sheet through the tagliatelle cutter. Alternatively, cut the sheet into manageable lengths, fold or roll it loosely without pressing, and slice it into ribbons approximately 6–8 mm wide.
6
Separate the tagliatelle immediately. Gently loosen the ribbons with your fingers and dust them lightly with flour to prevent them from sticking together. Arrange them in loose nests and repeat with the remaining coloured doughs.
7
Cook the rainbow tagliatelle in plenty of salted boiling water until al dente. Fresh pasta cooks quickly, so begin checking it after a few minutes. Drain and serve with your favourite sauce, keeping the dressing simple enough to let the different colours of the pasta stand out.
