Cook pasta according to package directions. Resevre 1/4 cup of the pasta water. In a pan, melt butter. Then add onion and cook for about 3 minutes, until soft. Add garlic and cook for 30 seconds. Add pasta, peas and reserved pasta water to the pan. Squeeze juice from 1/2 lemon over the pasta and use tongs to combine the mixture. Turn off heat and add lemon zest.
Separate the pasta onto two plates. Top each with prosciutto crumbles and a dollop of whipped feta. Top with fresh herbs and enjoy!