In a medium pot, boil a few cups of water. Once boiling, add peas and remove from the heat. Once the peas turn bright green (maybe 1-2 minutes), rinse them in cold water, drain, and set aside.
Rinse quinoa (if desired). In the same pot, bring 2 cups of chicken broth to a boil. Add quinoa, cover with lid, and reduce heat. Keep the pot at a low boil for about 15 minutes, until quinoa is fully cooked. Remove from the heat and allow to rest for 5 minutes.
Meanwhile, whisk together lemon juice, olive oil, minced garlic, oregano, and salt.
Fluff rested quinoa with a fork. Add peas, vinaigrette dressing, and feta cheese and stir together.