Preheat the oven to 180C/350F/Gas 4.
Dredge the fish in the seasoned flour.
Melt half of the butter in a large ovenproof frying pan. Add the skate wings and fry for three minutes on each side.
Transfer to the oven and cook for three minutes, or until just cooked through. Remove the skate wings from the pan and set aside on a warm plate.
Add the shallots to the same frying pan over a medium heat and cook until softened.
Add the capers and tomato purée and fry for two minutes.
Add the aniseed liqueur and fish stock and bring to the boil. Cook for five minutes.
Whisk in the remaining butter, then add the pine nuts.
To serve, place a skate wing onto each plate and spoon over the sauce. Serve with sautéed potatoes, lemon wedges and a sprinkling of fresh parsley.