Set a large skillet over medium-high heat and add the olive oil. Once the oil is hot, add the red onion and cook for about 2 minutes, stirring frequently, until softened.
Add the garlic and cook for 30 seconds, just until fragrant.
Stir in the quinoa, chickpeas, scallions, oregano, kosher salt, and black pepper. Pour in the vegetable broth and stir gently to combine.
Reduce the heat to low, cover, and simmer for 15 to 20 minutes, until the quinoa is just tender and the liquid is absorbed.
Stir in the spinach and cook just until wilted. It will look like a lot at first, but it softens quickly.
Stir in the lemon juice, adjust seasoning to taste, sprinkle with parsley, and serve warm.