Mix the paprika with the sage and rosemary in a shallow dish and season with a pinch of salt and plenty of pepper. Use this to lightly coat the chicken thighs.
Heat a large heavy-based pan or casserole on the hob over a medium heat. Add the oil and add the seasoned chicken thighs, presentation side down. Cook for a couple of minutes, then turn over with tongs and cook for another minute until sealed and lightly golden. Transfer to a plate.
Add the fennel and carrots to the pan with the tomato puree. Pour in the stock, scraping the bottom to remove any sediment. Stir in the potatoes and olives, then using tongs put the chicken on top.
Cover and cook on a low heat for 1 hour or until the chicken and potatoes are completely tender.
Arrange the braised chicken thighs with olives and serve with fennel fronds to garnish if liked.