Ingredients

• 2 large egg yolks
• 1 sheet frozen puff pastry (one 14 ounce package or half a 17.3 ounce package), thawed
• All-purpose flour (for dusting)
• 4 precooked pork sausages (such as andouille or kielbasa; about 1 pound), halved lengthwise
• 1/2 teaspoons baking soda
• Kosher salt and poppy seeds (for sprinkling)
• Whole grain Dijon mustard (for serving)

Instructions

1. Preheat oven to 400°. Mix yolks and 1 tablespoon water in a small bowl until smooth. Gently roll out puff pastry on a lightly floured surface just to press out any creases; brush with egg wash. Cut into 8 long strips. Lightly dust sausages with flour. Working one at a time, wrap pastry around sausage, egg wash side facing in. If pastry becomes too soft, chill until firm before continuing.
2. Place rolled-up sausages on a parchment-lined baking sheet, cut side down. Mix baking soda into remaining egg wash and brush over pastry (this will give dough a sheen); sprinkle with salt and poppy seeds. Chill 15 minutes.
3. Bake until pastry is puffed and golden brown, 25–30 minutes. Let cool. Slice into bite-size portions and serve with mustard.
4. Do ahead: Sausages can be rolled in pastry 1 day ahead. Cover and chill. Brush with egg wash and sprinkle with salt and poppy seeds just before baking.