For the zucchini with couscous and tuna, first prepare the couscous with the amount of water (indicated on the package). Before adding the couscous to the boiling water, stir in half the bouillon cube.
Let the couscous swell a bit and let it cool down. In the meantime, heat the oven to 200 degrees. Wash the zucchini and cut away the stem. Cut lengthwise and scrape out the insides with a coffee spoon until you have a nice groove.
Put the finished couscous in a mixing bowl, add the cheese and also add the tuna cans. Mix everything well. Now, preferably with wet fingers, generously fill the filling into the grooves and place in a baking dish.
When all the zucchini halves are ready, carefully pour some water into the mold until the zucchini halves are about halfway in the water bath. Bake the zucchini with couscous and tuna at 200 degrees for about 30 minutes.