Gently mix in a large bowl, the sourdough starter and 2 cups of warm water. Add 1 cup of rye flour. Cover with a cloth and let rise in a warm place for 1-2 days. Place the yeast in 1/4 cup of warm water and stir to dissolve. Add together with the salt to the sourdough mixture. Gradually add the rest of the rye flour and wheat flour. Stir to form a firm dough. Let the dough rest for 10 to 15 minutes, then knead on a floured surface until smooth. Brush the dough with olive oil and let rise in a warm place for 1 to 1 1/2 hours or until doubled in size.
Preheat the oven to 190°C (approximately 375°F).
Divide the dough into 2 halves and shape each half into a ball. Roll out into flat disks, about 2.5 cm (1 1/4 inches) in thickness. Roll the disks into 2 loaves and pinch to close at the seams. Before baking, dust the loaves with a little rye flour, then place on a lightly greased baking sheet. Prick the surface of the loaves several times with a fork. Cover with a cloth and let rise for another 30 minutes. Bake in a preheated oven for about 45 minutes or until the loaves are lightly browned.
Allow the loaves to cool. Slice the bread and enjoy with ham, cucumbers and tomatoes and serve.