Pulse the parmesan cheese cubes (probably don't even have to thaw them) until crumbled, then pulse the garlic until well chopped. Pulse the basil (washed and de-stemmed) until well chopped, then while the food processor is running, drizzle in a bit of olive oil to make it come together. Add about 1/4 tsp of salt and a few cracks of black pepper.

If freezing, seriously freeze the pesto in small dollops, either on a sheet pan or better yet, in the silicone cups. This way there will be less delicious pesto wasted.