Chop onion, heat pan and fry until transparent Chop tomatoes, add to onions until soft Stir in buckwheat and rice and cook for 1 minute Add remaining ingredients - bring to boil.
Heat oven to 375 * F. /190* C/Gas Mark 5 Simmer the mixture for 20 minutes until liquid has been absorbed Adjust seasoning, turn into 7" square cake tin Put in 5. above, leave for 30 minutes then remove.