Nice take on pesto. I usually toast my seeds on the toast setting in my small oven. I made half a recipe, and that fed 2 people (over 8 ounces of pasta). A little squeeze of lemon over the pasta really helped bring out the flavors.
WOW! This stuff is spoon-licking good, and what a striking green color! I've never had a pesto like this - very unique flavor and you can taste the pumpkin seeds! When toasting them on the stove, some popped like firecrackers which added some excitement to our evening. Note that when you make this your house will smell like the toasted pumpkin seeds...mmmm...great for fall or any time of year. On first taste, something was missing so I did add shaved mozzarella and a little more salt and that made all the difference (so vegans may want to have the substitute you mention on hand).