- In a small saucepan, brown the garlic in the oil. Add the tomato coulis, broth and bay leaf. Season with salt and pepper. Let simmer for 10 minutes. Remove the bay leaf. Set aside.
- With the rack in the middle position, preheat the oven to 375°F (190°C).
- On a work surface, with a small knife, cut off the top and seed the bell peppers. Cut the top off the eggplants, zucchini and onions. Scoop out the inside of the eggplants and zucchini and remove the middle layers of the onions, leaving about 1/4 inch (5 mm) of flesh inside the skin of all three vegetables (for the onion, leave 2 to 3 layers). If required, slightly trim the bottom so that the vegetables stand upright. Chop the flesh for the filling and set aside.
- In a lightly oiled baking dish, place the vegetables, open side up. Drizzle with the olive oil. Season with salt and pepper. Cover and bake for 25 minutes or until the vegetables are al dente (see note). Let cool.
- Meanwhile, in a skillet over medium heat, soften the chopped vegetables in the oil until almost dry. Transfer to a bowl. Add the remaining ingredients and season with salt and pepper. Stir well.
- Stuff the inside of the vegetables with the filling. Pour the tomato sauce at the bottom of the dish, and bake for 25 minutes or until the vegetables are soft and the filling golden brown. Let rest for 10 minutes.
If your baking dish does not come with a lid, cover with a sheet of aluminum foil.
To transform this into a main, simply add a scoop of ricotta cheese and serve with a toasted slice of country bread.