Clean the lamb stomach (if they are not already washed). Wash very well, use vinegar as well. 5-10 minutes after allowing the vinegar to soak, wash it off.
Wash off the intestines very well. Begin with the exterior and then wash the interior by placing one end of the intestine under running water and allowing it to pass through to the other side. With a knitting needle, we revert the inside layer of the intestines into the outside, thus effectively, flipping it inside out. Using the tip of the needle, we push the end of the intestine toward the center, until it has come through to the other side. Be careful not to tear the intestines and that long cords remain.
We then wash the intestines off again, by rubbing plenty of salt and lemon juice.
We place them in a basin and add some vinegar. We leave for 5 to 10 minutes and ten wash off very well with water. We slice a clean lemon and place between the intestines and the stomach.
Slice the stomach into 15x4cm pieces.
We wrap each stomach piece with one intestinal cord, until it is practically covered and then tie the intestine using both of its ends to ensure that it doesn’t unravel.
In a pot (or deep pan) we place olive oil and finely chopped onion so that they can sauté lightly and then add the gardoumpa that we have just wrapped.
After allowing the gardoumpa to sauté a little bit as well, we add one cup of water and for 30 minutes, allow to cook half-way.
We then add the tomatoes, salt, pepper and once they start boiling, add the zucchini.
We allow for 20 more minutes of cooking on low heat.