Melt the margarine in a saucepan and fry the mushrooms until cooked, then set aside.
In another saucepan, melt the butter and fry the shallots and garlic for a couple of minutes without colouring. Add the rice and stir well.
Pour in the wine and cook until the wine has disappeared.
Add a couple of ladles of stock to the rice and cook gently, on a low heat until the rice has absorbed all the stock, keep repeating until all the stock has gone, this will take around 20mins. Then season.
Add the mushrooms to the rice and stir well.
Fold in the teriyaki sauce, mascarpone and parmesan.
Spoon the risotto into bowls, grate some parmesan over the top and serve immediately.