Season chicken with paprika, salt and pepper. Heat oil in a large skillet. Place chicken in pan and brown on both sides. Remove to slow cooker. Add onion, carrots, celery, and mushrooms to pan. Season to taste with salt and pepper. Saute until vegetables are fragrant and any liquid evaporates, about 5 minutes. Scoop into slow cooker. Add potatoes, herbs, Roasted Garlic Tomato Sauce, and chicken broth to slow cooker and toss everything gently. Cover and cook on high for 4 hours.
You can substitute 1 1/2 cups chopped tomatoes for the Roasted Garlic Tomato Sauce if you like. If you do, add a few chopped garlic cloves to the vegetables when sauteing.