Preheat the oven to 325˚ and line a rimmed baking sheet with parchment paper. Whisk the egg white in a large bowl until frothy, then whisk in the sugar, thyme, chili powder, 1 1/4 teaspoons salt and a few grinds of pepper. Add the pepitas, pistachios and sesame seeds; toss to coat.
Spread the mixture in an even layer on the prepared baking sheet and bake, tossing halfway through, until crisp and dry, about 20 minutes. Remove from the oven, add the wasabi peas to the warm snack mixture and toss. Let cool.