Grinding up the everything bagel seasoning in a spice grinder will help it adhere to the almonds.
Preheat oven to 250°F.
Whisk egg white and seasoning in a medium bowl. Add almonds and toss to coat. Spread in an even layer on a large rimmed baking sheet.
Bake, stirring every 15 minutes, until dry, about 45 minutes. Let cool completely before storing, about 30 minutes.
To make ahead: Store in an airtight container for up to 2 weeks.