Position a rack in the center of the oven to 325°F Toss the seeds with the olive oil on a baking sheet large enough to hold them in a single layer. Spread in an even layer and roast the seeds in the oven, stirring occasionally, until golden, 13 to 15 minutes. Remove the pan from the oven and immediately toss the seeds with the coriander, salt, dill, pepper, and cayenne, if using. Let cool for 10 minutes. Transfer to a small serving dish or two and serve. If you’re working ahead, refresh the pepitas for a minute or two in the oven before serving. Makes 1 cup.