Preheat oven to 400°F.
Cut the ends off the zucchini, then turn sideways and and slice a thin strip off the tops with a knife.
Using a spoon, carefully scoop out the flesh, leaving shells to hold the stuffing. Chop the zucchini flesh and set aside.
Chop onion and mince garlic.
Heat 2 tablespoons of oil in a pan. Add the onion and garlic and sauté for 5 minutes or until golden brown.
Remove from the heat and let cool slightly. Stir in the zucchini flesh, cheese, walnuts, bread crumbs, egg, dill, salt, and pepper.
Stuff the zucchini shells and place side by side in an ovenproof dish; drizzle remaining oil over top.(Include any extra stuffing in the dish.)
Cover with foil and bake for 30 minutes, then remove foil and bake for another 10-15 minutes or until golden brown.
Serve with bread and peaches on the side.