Put the shiso, cheese, salt, olive oil, and lime juice, in a blender or the small work-bowl of a food processor and whirl it around until it's a fine green puree.
Boil the pasta according to the package directions in generously salted water. When the pasta is done, strain it well and toss it in a bowl adding the pesto a bit at a time until it reaches your desired level of flavor. Reserve the rest of the pesto for another time.
Plate the pasta and top with toasted pine nuts. You can also add some uni or ikura on top for some extra color and brine.