In a medium heavy saucepan, bring the 3 Cups stock to a boil and add quinoa. Cover and simmer until liquid is absorbed and quinoa is very tender. About 30 minutes. Set aside
Preheat oven to 400.
Oil the outside of the peppers and season the inside with salt and the cayenne pepper.
Trim bottom of peppers so they stand up in the casserole dish
Oil the casserole dish
Heat the olive oil in a large pan. Saute the onion, garlic, squash, and pumpkin seeds until they begin to get tender. Add the quinoa, spinach, and herbs and continue to sauté until blended. Add feta and mix well. Add a squeeze of lemon and Salt to taste.
Fill each pepper with the stuffing mixture and top with a few crumbles of feta and a few pumpkin seeds.
Place filled peppers in the prepared pan. Ad ½ C water or stock to pan and cover with foil. Bake 20-25 minutes until peppers are tender.