Season chicken thighs with dried oregano, paprika, salt, and red pepper flakes.
Heat a skillet over medium heat for 2 minutes. Add olive oil and chicken thighs. Cook for 5 minutes on one side.
Flip chicken, reduce heat, and cook until internal temperature reaches 165°F. Remove chicken from skillet.
In the same skillet, add tomatoes, garlic, oregano, salt, and olive oil. Cook for 2 minutes.
Add spinach until wilted, then mix in rice and chickpeas with lemon juice. Reheat, stirring occasionally.
Combine feta, olive oil, lemon juice, and oregano in a bowl.
Stir half the feta mixture into the skillet.
Top rice with chicken and remaining feta. Garnish with fresh oregano.