Start by making the couscous: add the water, salt, and butter to a pot. Bring to a boil, then stir in the couscous. Cover the pot and lower the heat. Cook on low heat for 8 to 10 minutes, stirring occasionally.
Once done cooking the couscous, remove from heat and add the spinach and feta cheese. Stir until incorporated and the feta cheese has melted.
Prepare the meatballs: Add the beef, onion, salt, pepper, garlic powder, parsley, and feta cheese to a bowl and mix until combined. Take a heaping tablespoon of the mix and shape it into a ball. Repeat until the mixture is finished.
For the full step-by-step instructions and video tutorial, download the Little Lunches app.