Season both sides of the chicken thighs generously with salt and freshly ground black pepper.
Heat the vegetable oil in a large nonstick skillet over medium-high until shimmery.
Arrange the thighs smooth side down without crowding the pan and cook 4–5 minutes until lightly browned; flip and cook 3–4 more minutes until the second side is browned. Transfer the chicken to a plate and set aside.
Reduce heat to medium, add the chopped onion and minced garlic to the skillet, and sauté 2–3 minutes until fragrant and beginning to soften, scraping up browned bits from the pan.
Add paprika, kosher salt, ground cumin, ground ginger, ground cinnamon, ground turmeric, and crushed saffron; stir until the onions are fully coated with the spices.
Add the orzo to the skillet and stir to coat it in the spiced onion mixture.
Pour in the chicken stock and bring the mixture to a simmer.
Return the seared chicken thighs to the skillet, nestling them into the orzo in a single layer.
Continue to cook, stirring occasionally to prevent sticking, about 8–10 minutes until the orzo is al dente and a thermometer in the thickest part of the largest thigh reads 165°F (74°C).
Remove the skillet from heat, stir in the lemon juice, lemon zest, and sliced olives, and let rest a minute to meld flavors.
Spoon onto plates and sprinkle with chopped parsley before serving.
