Heat oven to 250ºF (130ºC). Toss the pumpkin seeds in the olive oil to evenly coat. In a small bowl stir together the buttermilk, parsley, chives, garlic powder, onion powder, dill, salt and pepper.
Use a mortar and pestle to grind the spices. Toss the pumpkin seeds with the spice mixture and spread in an even single layer on a baking sheet.
Bake until the seeds are golden brown and crisp, about 30 minutes, shaking the pan about halfway through.
Store in an airtight container for up to two weeks.