In a small bowl, combine paprika, garlic powder, onion powder, salt, and pepper. Pat chicken thighs dry and season both sides with the spice mixture.
Heat olive oil in a large skillet over medium-high heat. Sear chicken thighs for 2-3 minutes per side until golden brown. Remove from heat and set aside.
Lightly coat the inside of a 6-7 quart slow cooker with cooking spray. Add crushed tomatoes, broth, and herbs de Provence to the bottom. Stir to combine.
Add potatoes, onion, carrots, and bell pepper on top of the tomato mixture. Stir gently to distribute vegetables evenly.
Place seared chicken thighs into the slow cooker, nestling them among the vegetables. Pour any accumulated juices from the plate over the top.
Cover and cook on LOW for 8 hours or HIGH for 4 hours. The chicken should reach an internal temperature of 165°F.
In the last 30-45 minutes of cooking, add sliced mushrooms and black olives. Gently stir to combine, recover, and continue cooking.
Once cooking is complete, turn off the slow cooker and let stand for 15 minutes before serving. Taste and adjust seasoning with additional salt and pepper if needed.
Serve hot, garnished with fresh chopped parsley. Enjoy over rice, pasta, or with crusty bread to soak up the delicious sauce.