Add everything but 1/4 cup pumpkin seeds (for garnish) to a food processor and blend on low to medium speed for 3-5 minutes until you reach your desired consistency. Avoid blending on high speeds or you will whip too much air into the salsa.
Salt to taste and serve with the reserved pepitas. (See notes for additional garnishing ideas.)
Notes
If you're working with a lower powered food processor or blender, you may want to roughly chop all your veg before blending. I added about 1 extra teaspoon of salt at the end. If you over salt, add extra lime juice or apple cider vinegar to balance the salsa.
On Tomatillos
Tomatillos are different from green tomatoes. They are more sour and tart than green tomatoes. Some describe the flavor profile as an herby green apple. If you're having trouble locating tomatillos, green tomatoes work as a substitute, but you may want to increase the acidity of your salsa with more lime juice or vinegar. Some prefer tomatillos grilled or cooked in salsas. If you have a smoker, I highly recommend my smoked salsa verde.
Optional Garnishes
To add sweetness (and make your salsa look even more beautiful), consider adding diced fruits like mango, pineapple, melon, or ripe tomatoes. Queso fresco or cotija cheese can add some saltiness and texture to your salsa.