Ingredients

· 12oz. short pasta

· 3tbsp olive oil

· 1 large onion, chopped

· Salt and pepper to taste

· 1 lemon

· ½ cup walnuts, toasted

· 1 clove garlic

· ¼ cup grated Parmesan, plus more for serving

· 1¼ cups frozen peas, thawed

· ½ cup rice vinegar

Method

Cook the pasta according to package directions. Reserve half cup cooking liquid, drain the pasta and return it to the pot. Meanwhile, heat a tablespoon of oil in a large skillet over medium heat; add onion, season with one-fourth teaspoon each of salt and pepper, cover and cook, stirring occasionally, until tender, for about six to eight minutes. While the onions are cooking, peel off three strips of zest from the lemon. Thinly slice them and add to a food processor along with walnuts and garlic, and pulse until finely chopped. Add Parmesan, one-fourth cup peas, remaining oil and half teaspoon each of salt and pepper; pure´e until smooth.

Add vinegar to the onions and simmer for two minutes. Add the remaining peas and toss until heated through. Toss in walnut pesto (add in some of the reserved cooking liquid if the pasta seems dry). Add the onion mixture and toss to combine. Serve with a squeeze of lemon juice and additional Parmesan, if desired.