Scoop the seeds and stringy bits from the pumpkin into a colander. Remove as many of the larger pieces of pumpkin flesh, then rinse seeds under water, removing as much of the orange flash and strings as possible. If a few bits remain, that's ok.
Bring a small saucepan of water to a boil, add 2 teaspoons of sea salt. When boiling, add the seeds and boil for 5-10 minutes.
Drain the seeds and place on a kitchen towel in an even layer. place a second towel over them and pat dry.
Line a baking sheet with foil or parchment paper. Spread the seeds on the baking sheet, drizzle with oil and season with 1/4 tsp salt. At this point you can also add spices if you wish.
Bake for 15-20 minutes, stirring halfway through.
Store in an airtight container at room temperature for up to 2 weeks.