1. Preheat your oven to 350°F (180°C).
2. Wash and cut the zucchini in half lengthwise, hollow them out with a spoon and keep the flesh.
3. Prepare a baking dish and pour 1/2 glass of water into the bottom, place the hollowed out zucchini.
4. Place in the oven.
5. Meanwhile, in the bowl of your food processor, put the zucchini flesh, onion, mushrooms cut into large cubes, and ham.
6. Roughly chop, it should not be too fine.
7. In a pan, sauté the mixture in olive oil for about ten minutes.
8. Beat the egg with 2 tablespoons of milk and add it to the pan.
9. Stir quickly and stop cooking.
10. Crumble the crackers.
11. Remove the dish from the oven and fill the zucchini with the stuffing.
12. Sprinkle with cracker crumbs and bake for about twenty minutes.
13. Serve hot.