Delicious mini Idaho® potato knishes, loaded with caramelized onions and spinach, make the perfect appetizer. They’re even better with a dollop of sour cream on top!
- 2 pounds Idaho® russet potatoes, peeled and quartered (4 medium)
- 2 tablespoons cooking oil, such as canola
- 2 tablespoons unsalted butter
- 3 medium yellow onions, peeled and diced (1 ½ pounds)
- 2 large eggs
- ⅓ cup matzo meal
- 5 ounces spinach leaves or baby spinach, slivered or roughly chopped
- Kosher salt
- freshly ground black pepper
- 8 ounces sour cream, to garnish
- Preheat oven to 375ºF and set oven racks in the top and bottom of the oven.
- Spray or lightly oil two baking sheet pans. Set up a food processor with the chopping blade.
- Place potatoes and 2 teaspoons salt in a large pot and cover with cold water by an inch. Bring to a boil and cook for 20 minutes or until potatoes are tender. Drain, mash well, and set aside to cool.
- Melt butter with oil over medium heat in a large skillet. Cook onions, stirring occasionally, for 20 minutes, to brown. Scrape onions into the bowl of the food processor. (Don't clean the skillet - you'll use it for the spinach.) Add eggs, 1 teaspoon of salt and 1/4 teaspoon of pepper to onions and pulse several times, until the onions are finely chopped. Scrape the onion-egg mixture into the bowl with the potatoes. Add matzo meal. Mix thoroughly and set aside.
- Add the chopped spinach to the skillet and sauté over medium heat, stirring constantly, until wilted (a minute or two), add wilted spinach to the potato mixture and stir through.
- Scoop up a heaping tablespoon of potato mixture, roll it into a ping pong-sized ball and place it on one of the prepared pans. Repeat until you've used up all the potato mixture, spacing the balls about 1/2 inch apart. You should get about 50 pieces.
- Push your thumb down on the center of each ball to flatten it slightly and make a depression similar to how you'd make thumbprint cookies.
- Bake knishes for 30 minutes in the top and bottom of the oven, switching the position of the trays half way through. Turn the oven up to broil and cook 2-3 minutes, checking every minute, until the knishes on the top shelf get some nice brown spots. Switch the position of the trays and let the second tray of knishes brown for a minute or two.
- Remove trays from oven and let knishes cool for 10-15 minutes. Set knishes out on a platter or serving tray. Dollop a little sour cream in the center of each knish and serve.
Time Saving Tip: The potato-spinach mixture can be made up to a day ahead and kept covered in the fridge. Then roll and bake just before serving.