Sift flours and baking powder into a large bowl, stir in linseeds and add freshly ground black pepper. In another bowl whisk eggs and milk and stir in parsley and chives. Make a well in the centre of the flour and pour in egg mixture and whisk slowly until all the flour is mixed. Chill for 30 minutes. Stir mixture again. Pour into a jug.
Heat cooking spray in a large frying pan and add two ¼-cup amounts of mixture to the pan. Cook for 1 to 2 minutes each side, until golden, on a low–medium heat. Remove, keep warm. Continue with remaining mixture, wiping pan between each batch with paper towels and respraying the pan. Do not spray towards direct heat.
Roast whole tomatoes or roast, grill or pan-fry halved tomatoes until cooked. Sprinkle on freshly ground black pepper.
Meanwhile, heat oil in a large frying pan and cook leek and thyme for 4 to 5 minutes until leek is soft. Add mushrooms and cook for 3 to 4 minutes until mushrooms are soft. Stir through balsamic vinegar, parsley and freshly ground black pepper. Use a slotted spoon to serve.
Serve pancakes with balsamic mushrooms and leek, and tomatoes.