1. In medium bowl, toss onions with lemon juice. Let sit about 30 minutes.
2. Add peas to stock pot and pour water over top until just covered. Place lid on pot and cook over medium-high heat about 10 minutes. Peas are ready when they “give” when pressed between your fingers. Drain.
3. Combine peas with pasta and toss with pesto. Top with tomatoes, cucumbers, avocados, onions, olive oil, and vinegar. Gently toss. Serve with Parmesan and a dollop of pesto on the side. Serves 4.