Rehydrate the soya mince. Add the dried soya crumbles (TVP) to a bowl with vegetable broth. Let it sit for 10 minutes while you prepare the veggies.
Prep the veggies. Finely mince the onion. Cut the zucchinis lengthwise in half. Scoop out the flesh with a teaspoon to form the zucchini boats.
Drain the soya mince. The soya crumbles should have absorbed all or most of the liquid. Drain them through a fine-mesh sieve that you placed over your sink and press out any excess liquid with your hands.
Preheat the oven to 350°F (180°C).
Sauté. Heat a large pan with olive oil. Sauté the onion for 2-3 minutes over medium-high heat until soft. Add in the soya crumbles and tamari. Sauté for another 2 minutes.
Make the filling. Add the chopped zucchini flesh, oregano, and garlic powder to the pan. Sauté for 5 minutes over medium heat. Add in the marinara and let it cook for 2 more minutes.
Make the zucchini boats. Place the zucchini on a parchment-lined baking sheet. Divide the filling into the hollowed-out zucchinis.
Bake for 35-40 minutes at 350°F (180°C), fan mode.
Optionally, serve with cooked white rice, fresh basil, and vegan parmesan cheese.