In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté until translucent, about 3-4 minutes. Add minced garlic and sauté for another minute until fragrant.

Pour in the chicken broth and bring to a boil. Once boiling, stir in the orzo pasta. Reduce heat to medium-low and let simmer for about 10-12 minutes, stirring occasionally.

Once the orzo is al dente, add the shredded chicken and chopped spinach to the pot. Cook for an additional 5 minutes until the spinach has wilted.

Stir in the crumbled feta cheese and lemon juice. Season with salt and pepper as needed. Let everything meld for a few minutes before serving.

Ladle the soup into bowls, add an extra sprinkle of feta, and perhaps a drizzle of olive oil for a finishing touch.