Cut the vegetables into batons, then blanch them in boiling salted water, leaving them slightly firm in the centre. Sweat the onion in a pan with a little butter, turmeric and curry powder until soft and transparent. Add the chopped tomatoes and cook for 5 minutes. Add the blanched vegetables and breadcrumbs and mix thoroughly. Adjust seasoning, remove from the heat and allow to cool. Unfold the filo pastry and using a pastry brush, brush one sheet with some of the melted butter. Place another sheet on top and carefully rub smooth with your hands. Repeat twice so you have 3 x 2-ply sheets. Now brush the edges of the longer sides with butter and join them together to make one big rectangle. Spread the vegetable mix down the centre and fold in strudel fashion. Brush the top with egg yolk and sprinkle with salt. Bake in the oven at 350F for 30 minutes until crisp golden brown. To make the mash, boil and mash the potatoes, and beat in the butter, cream and milk until light and fluffy. Finally beat in the horseradish sauce. Slice the strudel on the slant into thick slices and serve with the mash. DISCLAIMER(c) Copyright 1996 - SelecTV Cable Limited. All rights reserved. Carlton Food Network http://www.cfn.co.uk/