Sauté the chopped onions with a generous amount of olive oil. The oil will moisten the liver so at least a few tablespoons. Sauté till onions are a deep golden brown, about 20-30 minutes.
Combine onions and oil from pan, eggs, peas, walnuts, salt and pepper in a food processor. Process till mixture is combined and smooth. When you taste, mixture should have no lumps or pieces of nuts visible. It should be a lovely smooth greenish mixture. Add mayonnaise if mixture needs to be smoother and process till ingredients are completely smooth. Taste to add more salt and pepper to taste. Put in refrigerator and serve cold with veggie sticks and crackers.