Chop the garlic in a food processor.
Add the arugula, spinach and basil and process for a minute or two until they are minced.
Add the tahini, miso and vinegar. Continue to process until smoot and creamy.
Transfer the pesto to a small bowl and set aside.
Cook the Pasta in boiling water, following the package directions. Drain it, saving 1/2 a cup of the water.
Transfer the pasta to a large shallow bowl.
Mix the saved hot pasta liquid with the pesto which was set aside earlier in the small bowl. Add this mixture to the large bowl, tossing it to coat the pasta.
Top with the roasted summer vegetables and sprinkle with vegan parmesan bits.