I would normally add parsley to a basil pesto, its seems to alleviate the bitterness that can occur when chopping basil with a steel food processor blade (not the correct way but the quick way). Using the processor allows me to make pesto in bulk (literally bucket loads) and easily vary the consistency according to preference (chunky or smooth). I add it to vegie or meat sauces, mayo to dress coleslaw, lasagna, or spread it onto pizza bases. Recently I made some potato and spinach gnocchi and dressed it with parsley pesto which was feast of green! (that nobody complained about, much...)
3 cups of chopped parsley
1 cup of cashews ( i buy the broken ones much more affordable than pine nuts)
2/3 extra virgin olive oil
1-2 gloves of garlic
1 cup grated parmesan
pinch of salt
Process according to preference. Store in sealed containers in the fridge for a week (longer if you pour more oil over the top) or freeze. When adding to pasta retain some of the cooking water and/or add some olive oil to encourage good coverage.