Photo of Mollie Katzen

Leftover Mashed Potato-Broccoli-Walnut Cakes

Leftover Mashed Potato-Broccoli-Walnut Cakes

Green-speckled and soft on the inside, golden and crisp on the outside – this is how to embed broccoli in mashed potatoes and come up with something exceeding the sum of its parts.

To grind the walnuts, pulse them in short spurts in a food processor until they resemble coarse breadcrumbs (slightly coarser than polenta).

Regarding the range of mustard and garlic: use lesser amounts (say, starting with half) if you like milder flavor. Go for the full amount if your palate is adventurous.

Ingredients

  • 2 cups finely minced broccoli florets and peeled stems
  • 1 3/4 cups leftover mashed potatoes
  • 2 tablespoons prepared mustard (plain yellow, or Dijon)
  • Up to 1 teaspoon minced or crushed garlic
  • 1/2 cup very finely minced scallions (whites and reasonable greens)
  • Up to 1/2 teaspoon salt (or to taste)
  • Black pepper
  • 1 1/2 cups ground California walnuts
  • 1/4 cup olive oil, grapeseed oil, or high-oleic safflower oil
  • A touch of unsalted butter (optional)

Directions

  1. Heat a kettle of water to boiling. Have the broccoli set up in a colander sitting in a large bowl in the sink, and when the water boils, pour it into the broccoli to cook it slightly. Let sit for 2 minutes then drain well, shaking off all the excess water. Transfer the broccoli to a clean tea towel – spreading it out and patting it to dry it completely. Return the colander to the sink (no need to clean it at this point).
  2. Place the mashed potatoes in a medium-sized bowl. Add the broccoli, mustard, garlic, scallions, 1/2 teaspoon salt, if necessary, and pepper. Mix until everything is thoroughly blended, then taste to see if it needs more salt.
  3. Use your hands (wet them, if you like, for easier handling) to form the mixture into 3-inch patties—about 1/4 cup apiece. 
  4. Have the ground walnuts ready and waiting on a dinner plate. Press each patty gently but firmly into the ground walnuts to coat the entire outer surface, both sides. It’s okay to coat them generously. (You might not use them all.) Chill patties very well (they can be prepared to this stage and refrigerated).
  5. Place a 10-inch skillet over medium heat and wait about a minute. Add the oil, and swirl to coat the pan.  If you’d like, you can also melt in some butter.
  6. When the oil is hot enough to instantly sizzle a walnut crumb, fry the cakes (in batches, as space allows) for about 5 minutes on each side, or until golden and crisp all over.  You want to heat them through (remember, they are already cooked) and get the walnuts golden and toasty, but not dark. (Wipe out the pan between batches, to sweep away any possibly overdone walnuts that might be left behind. Add more oil, as needed, per batch.) Serve hot or warm.