2) Cook the bacon and walnuts in a large oven-proof frying-pan over a medium heat until the bacon just begins to crisp and the walnuts are toasted, about four minutes. With a slotted spoon, transfer the bacon and walnuts to a bowl and set aside. Add the Brussels sprouts to the skillet and season with salt and pepper.
3) Place the pan in the oven and roast for about 30 minutes. Add the bacon and walnuts and continue to roast until the sprouts are cooked through and golden, about 10 to 15 minutes more.