Bring a large pot of water to a boil, salt it well.
Run your beet pasta through a pasta maker until it is as thin as you can get it. One sheet at a time, transfer pasta to a floured work surface.
If you don't have a pasta maker, just roll it out on a floured surface.
Drop a bit of filling (½ – 1 teaspoon) along the middle of the pasta sheet, leaving an inch or two between each drop.
Use a pastry brush to brush a little whisked egg around each drop of filling
Carefully place a second sheet of dough on top of the first, sandwiching the filling between them.
Lightly press down on the filling lumps, pressing down on the surrounding dough to seal. Be sure to push out as much air as you can, as you go.
Use a knife or a pastry wheel to trim the pasta into squares.
Press edges of each square firmly together to seal.
Transfer ravioli to boiling water in batches, cooking for 3-5 minutes or until they float to the surface. Strain well.
Serve ravioli hot, topped with basil cream sauce and walnuts.