Pat chicken thighs dry and season both sides generously with salt and freshly ground black pepper.
Heat the vegetable oil in a large nonstick skillet over medium-high heat until shimmering.
Arrange the chicken thighs smooth side down without crowding the pan and cook 4–5 minutes until lightly browned; flip and cook 3–4 minutes more until the other side is browned. Transfer chicken to a plate and set aside.
Reduce heat to medium and add the chopped onion and minced garlic to the skillet; 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 and garlic are evenly coated with the spices.
Stir in the orzo to coat with the spiced onion mixture.
Pour in the chicken stock and bring the mixture to a gentle simmer.
Nestle the browned chicken thighs back into the skillet in a single layer, pressing them down slightly into the orzo.
Continue to simmer, stirring occasionally to prevent sticking, about 8–10 minutes or until the orzo is al dente and an instant-read thermometer inserted into the thickest part of the largest thigh reaches 165°F (74°C).
Stir in the lemon juice, lemon zest, and sliced olives, then remove the skillet from the heat.
Spoon portions onto plates and sprinkle with the chopped parsley before serving warm.