In a bowl
combine 1 cup plain bread crumbs, 1 cup grated Parmesan, zest of 1 lemon, 1/2 cup finely chopped flat-leaf parsley, 1 tbsp dried oregano and 2 tsp dried basil; set aside. Heat 3 tbsp olive oil
in a large nonstick skillet
over medium-high heat. Add 1 1/2 cups finely chopped onion, 1 large (1 1/2 lb) eggplant, unpeeled and diced 1/4 inch, and 2 1/2 tsp kosher salt; stir to coat with oil. Cook, stirring occasionally, until soft, 8 to 10 minutes. Remove from heat; add 1 1/2 cups (5 1/2 oz) finely chopped toasted walnuts, 3 minced garlic cloves and 2 tbsp tomato paste. Transfer half the mixture to a food processor
and blend until smooth. Stir together eggplant mixture with puree, bread crumb mixture and 1 beaten egg in a large bowl. Generously coat hands with oil and form into 1 1/2 inch balls; place on a baking sheet
1/2 inch apart. Continue to coat hands with oil to form balls. Freeze, or bake at 350 degrees F on a lightly greased baking sheet until cooked through, 25 to 30 minutes.