Put the margarine in a very large bowl. Cook in the microwave on full power for 30 seconds or until melted. Stir the onion and celery into the margarine and cook on full power for 5 minutes, stirring once, until just beginning to brown. Mix the peanuts into the softened vegetables. Cook on full power for 7 minutes until the roasted smell of the nuts is noticeable. Add carrot, mushrooms, marmite, fruity sauce and stock. Cook on full power for 7 minutes or until the vegetables are soft. Stir twice during cooking. Stir in the oats and season with pepper. Cook on full power for 3 minutes until the mixture is thick but mushy. Mix in the besan flour.

Turn the mixture into a 455 grams / 1 pound loaf dish. Cook on full power for 8-10 minutes until the loaf browns on top and begins to firm up. Leave for 10 minutes before turning out.

Serve with tomato and sage or tomato and horseradish sauce.