Sift the dry ingredients together into a bowl, and make a well in the centre. Pour in the water, oil, tomato purée and pieces of tomato, if using, and mix until you have a fairly slack dough. Using extra flour on the worktop, knead until the dough is smooth, satiny and elastic. Place in a greased bowl, cover with a clean, damp tea-towel, and leave to rise until at least doubled in volume. This can be done overnight in the refrigerator or in a couple of hours at normal room temperature. If the weather is hot and dry, you may need to remoisten the tea-towel to prevent a hard crust forming on the dough. While the dough is rising, prepare the filling.
Mix all the filling ingredients together, except for the sunflower oil, stripping the herbs from their stems and chopping as necessary. Roll into a slightly flattened sausage shape of a size that will fit your frying pan. Fry the meat all over in the sunflower oil to brown it, remove from the pan, and put aside to cool.
Turn the dough on to a floured worktop, knock it back and knead it smooth again. Roll it out to a square large enough to enclose the sausage. Wet the edges. Spread the dough with Dijon mustard, place the sausage in the centre, and draw the two edges over, pinching together to seal. Close the two ends as well, and turn the sausage loaf on to a greased baking sheet, with the seam underneath. Slash lightly in two or three places, and brush if you like with a milk and egg yolk glaze. Bake in a preheated oven at 200°C / 400°F / Mark 6 for 15 minutes, and then turn down to 170°C / 325°F / Mark 3 for a further 15 minutes. Cool on a wire rack, before slicing and serving. It can be served warm or cold, and makes a very good picnic or buffet dish.
© 1995 Frances Bissell. All rights reserved.