Kasha & Mushroom Knishes

Knishes are the Ashkenazi Jewish answer to a savory hand pie, and this vegetarian version skips the traditional potato in favor of kasha (toasted buckwheat groats with a deep, nutty, almost earthy flavor). The filling pulls in caramelized onions and chopped mushrooms, which amplify that woodsy, grown-up character.

The kasha technique is the critical step. Tossing the grains with beaten egg (or egg substitute) and dry-toasting in a hot pan before adding liquid is what gives proper kasha its signature separate grains instead of a mushy porridge.

Frozen puff pastry replaces the traditional knish dough here, which is a shortcut that gives you crisp, golden layers without rolling out anything fussy.

Seam-side down on the baking sheet matters. Put the pinched edge on the bottom and gravity keeps it sealed through baking.

Kitchen Tips

• Don’t skip the egg-toss on the kasha. Without it, the grains clump into a sticky mass instead of staying fluffy.
• Let the filling cool to room temperature before assembling. Warm filling melts the pastry and sabotages the puff.
• Pinch the pastry edges firmly. Loose seams split open in the oven and leak filling.
• For a golden-brown finish, brush with real beaten egg instead of egg substitute. Real egg browns better.

Variations

• Swap kasha for mashed potato and fried onions for the classic New York deli-style knish.
• Add crumbled feta or grated Parmesan to the filling for a non-traditional cheesy upgrade.
• Dust with sesame seeds or flaky salt instead of (or alongside) the poppy seeds.