Cook the tagliatelle in plenty of salted water according to the instructions on the packet until al dente.
In the meantime, for the pesto, pluck the basil, rinse and dry a little. In a tall container, mix with the olive oil, pine nuts and 1/2 teaspoon each of salt, pepper and sugar with a hand blender to a homogeneous mass. Grate the parmesan and fold in with a spoon.
Mix the finished noodles with the pesto and arrange on plates together with a few halved cocktail tomatoes and feta cubes.