As pepitas toast, they puff up, forming a light, crisp outer shell and a slightly chewy center. The floral notes of the lime balance the spicy jalapeño, making this a great bar snack to pair with Mexican lagers or tequila-based cocktails.
Preheat oven to 350°F. Combine pepitas, jalapeño slices, oil, and coriander seeds on a rimmed baking sheet; toss to coat. Spread mixture in a single layer. Bake in preheated oven until pepitas are toasted and mostly golden, 15 to 25 minutes, stirring every 5 minutes.
Sprinkle mixture with lime juice and 1/2 teaspoon salt; toss to coat. Spread mixture in a single layer, and bake at 350°F until lime juice has completely evaporated and pepitas are crisp, 3 to 5 minutes.
Spread pepitas in a single layer on paper towels. Sprinkle with remaining 1/2 teaspoon salt or more to taste. Let cool completely, about 30 minutes.
Pepitas may be stored in an airtight container at room temperature up to 8 hours or overnight.