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pile of cut up knishes filled with root vegetable mash
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5 from 10 votes

Knish Recipe with Root Vegetable Mash

This knish recipe is filled with a delicious root vegetable mash, wrapped in a golden flaky puff pastry (store-bought - shh). Melt in your mouth and really easy. A great make ahead side dish or appetizer.
Prep Time10 mins
Cook Time1 hr
Total Time1 hr 10 mins
Course: Appetizer, Side Dish
Cuisine: American, Jewish
Servings (change as needed): 34 pieces approximately
Author: Cheryl

Ingredients

For Root vegetable mash

  • 2 pounds (0.9kg) root vegetables Note 1 (this will make a bit more than you need)
  • 2 tablespoon butter (or neutral oil) use 3 tablespoon butter for extra richness)
  • 2 tablespoon -3 milk or cream (optional)
  • 2 green onions, finely chopped
  • salt and pepper

For knish assembly

  • 1 package puff pastry dough (2 sheets), defrosted if frozen about 14-17 ounces pastry dough in total
  • 3 ½ cups root vegetable mash (made with ingredients above) cold leftovers is fine
  • 1 egg plus one tablespoon water, mixed (for egg wash)

Instructions

  • Heat oven to 375F.
  • MAKE ROOT VEGETABLE FILLING:  (can be done 2-3 days ahead)
    °Prep and boil: Cut veggies into roughly the same size - about 1 - 1 ½ inches. If using carrots, slice them thinner as they take longer to cook. Place in pot and add water to cover by 1 inch. Add 2 teaspoon salt. Bring to boil. Lower to medium and gently boil for 15-18 minutes or until soft and easily pierced with a fork. Drain vegetables in a colander and return to the pot.
    °Mash: On medium heat, shake cooked vegetables to dry them out for 1 minute. Add green onions, butter and milk/cream. Mash with a fork to get the consistency you like. Do not use a food processor or immersion blender to mash veggies. Taste and add salt and pepper as needed. Set aside or store in fridge until ready to make knishes.
  • ASSEMBLE KNISHES: On a lightly floured cutting board, unroll one sheet of dough. It should be about ⅛-1/4 inch thick. Stretch it out a bit to make a rectangle. Spread a log of vegetable mash mixture along the longer side of the rectangle - about 2 inches thick. Roll dough over the vegetable mixture about 1 and ½ times, making a log/roll. Cut away rest of dough for the next roll. Pinch seams together well. Repeat with other half of dough on that sheet. Then do the same with the second sheet of dough. You will have 4 logs/rolls in total.
    one roll of filled puff pastry with second not yet rolled up
  • BAKE: Place filled knish rolls - 2 inches apart - on a large parchment-lined pan, seam side down. Brush egg wash on rolls to create a glazed golden look. Bake for 35-40 minutes until golden brown and flaky. Cut rolls into 2 inch pieces on the diagonal and serve. Or see Note 2 for make ahead options.

Notes

  1. Root Vegetables: Use two or more – white potatoes (I like Yukon/yellow potatoes best), sweet potatoes, carrots, parsnips, turnips, rutabaga (swede), celery root (celeriac). If you don't have a scale, don't worry. Leftovers are great. Try two white potatoes, 1 medium sweet potato, 2 medium carrots, 2 parsnips and a turnip. 
  2. Make Ahead options:
    1. Make root vegetable mash 2-3 days ahead and keep it in a sealed container. 
    2. Make the knish rolls up to 2 months ahead and freeze them as logs, unbaked, wrapped well in parchment and ziploc bags or foil.  Bake as per instructions whenever you need them (no need to defrost).
    3. Make the knish recipe a couple of hours before you need them including baking and cutting into serving pieces. Keep them in the counter. Reheat in the pan in a pre-heated 350F oven for 6-8 minutes.  (I do this all the time and think it's the best way - they get even  crispier/flakier.)
 
Nutrition values are rough estimates depending on on puff pastry dough used and how root vegetable mash is made eg amount of butter and milk/cream used.  
Calories: 106kcal | Carbohydrates: 11g | Protein: 1g | Fat: 6g | Saturated Fat: 2g | Cholesterol: 2mg | Sodium: 45mg | Potassium: 112mg | Fiber: 2g | Sugar: 1g | Vitamin A: 28IU | Vitamin C: 5mg | Calcium: 13mg | Iron: 1mg