Start by preparing the zucchinis. Cut the top of the zucchinis and remove the pulp from the inside with a teaspoon, leaving a margin of about 0.5 cm. Also remove some of the pulp from the tops, to leave them slightly rounded. Chop the zucchinis pulp and set aside.
Preheat the oven to 180° C. In a large skillet, heat a tablespoon of olive oil over medium heat and add the onion. Cook 1 to 2 minutes, until translucent. Add the garlic, pepper and rosemary and cook for 3 more minutes, stirring occasionally. Increase heat to medium-high and add the meat. Cook, stirring occasionally, until the meat is no longer pink. Add the zucchinis pulp and season with salt and black pepper. Cook for 8 to 10 minutes to dry the mixture, stirring frequently.
Divide the filling by the zucchinis and take to bake in the oven for 45 minutes (put the stuffed zucchinis and their "caps" in the roasting tray side by side, so that the filling will be toasted on top. To serve, then place the "caps" on the zucchinis).
To make the couscous, boil 1 cup of water. In a large bowl, place a cup of couscous and season with 1 tablespoon of olive oil, salt, ground nutmeg and black pepper. Pour boiling water over and cover (with a plate, for example). After 3 minutes, uncover and stir with a fork to loosen the grains.
When the zucchinis are ready serve immediately, accompanied with the couscous.