In a large saucepan, heat the olive oil and gently fry the leeks, for 3-4 minutes until soft. Stir in the garlic and arborio rice, and cook for a further minute.
Make up 1.3 litres hot vegetable stock using the stock cube and add to the pan, 1 ladle at a time, stirring frequently and adding more as the rice absorbs the liquid. Cook slowly over a low heat for about 20 minutes, until all the stock is absorbed and the rice is cooked.
Just before serving, stir the smoked salmon trimmings and light soft cheese with garlic & herbs through the risotto. Squeeze over the juice of half the lemon and cut the remaining half into four wedges. Season the risotto with freshly ground black pepper. Spoon into bowls and serve each dish with a lemon wedge.
Cook's tip: for a vegetarian dish, try swapping the salmon for 200g of cherry tomatoes, roasted.