Start off with making the risotto as that takes some time and dedication to do. In a preheated pan put 1 tablespoon of butter, 1 tablespoon of olive oil and onions and fry until soft Add the sun-dried tomatoes, garlic, basil, prawns and risotto rice and continue to cook for 5 minutes. Add the white wine and reduce by half. Immediately turn down the heat to low and add half of the fish stock. It is very important that you continue stirring almost all of the time. When the risotto starts thickening, add the remaining fish stock and allow to reduce, stirring occasionally. Meanwhile, place a griddle pan over high heat and add the remaining butter. Add the salmon fillet to the pan and sear for 5 minutes on each side. When the risotto is cooked, stir in the mascarpone cheese if using and serve into a large deep pasta plate with the seared salmon on top.