Wash and cut 4 medium zucchini in half lengthwise.Scoop out some of the flesh of the zucchini and chop it finely with a knife or in a food processor. Also, finely chop onionandgarlic.
Preheat the oven to 400°F or 200°C.In a large skillet, warm up 1 tablespoon extra virgin olive oil and gently fry 1 medium onion (chopped) for 3 minutes, then add 3 cloves garlic (grated) and chopped zucchini pulp and cook for 5 minutes.
Add 1 can (15 oz) lentils (drained and rinsed), ½ cup walnuts (chopped), 1 can (15 oz) crushed tomatoes, 2 tablespoons soy sauce, ½ teaspoon dried oregano, 1 teaspoon salt, and 2 twists black pepper.Simmer for 10 minutes on medium to low heat, stirring occasionally.
After 10 minutes, your filling should be rich, tasty, and thick. Taste and adjust for salt and spices.
Fill the zucchini shells with the lentil mixture and arrange them on a baking tray.Drizzle with olive oil and bake at 400°F or 200°C for about 25 minutes; then sprinkle them with grated parmesan, and bake for 5 more minutes until the cheese melts.
Garnish with freshly parsley or and a squeeze of lemon juice.