Heat the olive oil in a large pot or Dutch oven over medium heat.
Season the chicken thighs with salt and pepper. Add them to the pot, skin-side down, and cook for about 5 minutes until browned. Flip and cook for another 5 minutes. Remove the chicken and set aside.
In the same pot, add the diced onion and sauté for 3-4 minutes until softened. Add the minced garlic and sauté for another minute.
Stir in the rice, coating it well with the onion and garlic mixture. Cook for 1-2 minutes until the rice is slightly toasted.
Pour in the chicken broth, then add the frozen peas and carrots, dried thyme, and paprika. Stir to combine.
Return the chicken thighs to the pot, skin-side up, and bring to a simmer. Cover the pot with a lid, reduce the heat to low, and cook for 25 minutes or until the rice is tender and the chicken is cooked through.
Once cooked, remove from heat and let it sit, covered, for 5 minutes. Squeeze fresh lemon juice over the top and garnish with chopped parsley if desired before serving.