Chef John's Meatless Meatballs

Make vegetarian meatballs with browned mushrooms instead of meat and you'll be amazed by their hearty taste and perfect texture. Approved for use on spaghetti!

Heat olive oil in a skillet over medium-high heat. Add mushrooms to the hot oil, sprinkle with salt, and cook and stir until liquid from mushrooms has evaporated. Stir butter into mushrooms,...

Ingredients

• 1 tablespoon olive oil
• 1 pound fresh white mushrooms, finely chopped
• 1 pinch salt
• 1 tablespoon butter
• 1/2 cup finely chopped onion
• 4 cloves garlic, minced
• 1/2 cup quick-cooking oats
• 1 ounce very finely shredded Parmigiano-Reggiano cheese
• 1/2 cup bread crumbs
• 1/4 cup chopped flat-leaf (Italian) parsley, packed
• 2 eggs, divided
• 1 teaspoon salt
• freshly ground black pepper to taste
• 1 pinch cayenne pepper, or to taste
• 1 pinch dried oregano
• 3 cups pasta sauce
• 1 tablespoon very finely shredded Parmigiano-Reggiano cheese, or to taste
• 1 tablespoon chopped flat-leaf (Italian) parsley, or to taste