Heat the olive oil in a large pot over medium-high heat. Sauté the onions for about 5-7 minutes, or until translucent. Add the garlic, 2 tablespoons of dill, and 2 tablespoons of chives. Sauté for another minute or two.
Add the spinach, and cook for 3-4 minutes, just until it wilts down.
Add the salt, pepper, basmati rice, and vegetable broth and stir. Bring it to a boil, cover with a lid, and reduce the heat to medium-low. Simmer for 20 minutes.
Stir in the butter, lemon juice and zest, and the remaining dill and chives.
Garnish with feta cheese and lemon wedges. Serve.