1. Preheat the oven to 400°F. Cut the zucchinis in half lengthwise and use a small spoon to hollow out the centers. Blanch them in boiling water for 1 minute and drain well.

2. Finely chop the zucchini flesh and put it in a saucepan with the oil and garlic. Cook over medium heat, stirring, until it softens but does not brown.

3. Add the lemon grass, lemon zest, lemon juice, rice, tomatoes, cashews, and thyme. Add the cognac. Season with salt and pepper, and fill the zucchini shells. Place them in an oven-safe dish and cover with aluminum foil.

4. Bake for 25 minutes, or until the zucchinis are tender. Serve hot.