Shell the pistachios.
(optional) Put the cherry tomatoes in boiling water to peel them.
(optional) Put them straight away in cold water to cool them and ease the peeling.
(optional) Peel them using a serrate knife.
Put the pasta in salted boiling water and cook it al dente (i.e roughly 2 minutes under the time on the box).
Put the cherry tomatoes in a pan with olive oil, poached garlic and basil leaves. (Cut them in half if not peeled).
Prepare the pesto: put the pistachios and the parmigiano in a cylindrical container and add the olive oil little at a time while mixing with an immersion blender. Add the cold water afterwards.
The cream should look like this. Adjust with other cold water if you think it is too dense (be careful, you can always add it, but not remove it).
Remove the garlic and put the pasta in the pan with tomatoes.
Add half a ladle of water from the cooking, and cook for another minute.
Add the pesto.
Mix it out of the cooker, adding other cooking water if necessary.