Heat a non-stick frying pan and when hot add the butter and oil.
Season the chicken livers with salt and freshly ground black pepper and place into the pan with the shallot and garlic. Cook for 3-4 minutes, turning occasionally to brown all over.
Add the sherry and the mustard and stir well.
Lift the livers out and set aside.
Add the spinach to the pan with a tablespoon of water and cook for a minute.
Add the peas and season with salt and freshly ground black pepper and some grated nutmeg. Cook until the spinach has wilted, then add the lemon juice.
Return the livers to the pan and stir together.
Season, to taste, with salt and freshly ground black pepper, then pour out onto a plate. Serve with crushed new potatoes.
