To the bowl of your food processor add the basil leaves, spinach, oregano, garlic, and almonds. Pulse 5-6 times until the ingredients have broken up substantially. With the food processor running on low to medium-low, drizzle in the olive oil. Continue drizzling until the pesto just comes together. Add more as needed. Season the pesto with salt and black pepper, and add the grated parmesan cheese to the mix. Pulse again 5-6 times until the cheese is incorporated.