Heat the oil in a large pot or Dutch oven over medium heat.
Add the diced onion and cook for 3-4 minutes, until softened and translucent.
Stir in the minced garlic, diced tomatoes, fresh basil, thyme, and chili pepper (or flakes).
Cook for another 3 minutes, stirring occasionally, until fragrant.
Pour in the vegetable stock and add the amaranth.
Bring the mixture to a boil, then reduce the heat to low, cover, and let it simmer for 20 minutes.
Add the corn kernels and diced zucchini to the pot. Increase the heat to bring the soup back to a simmer, then cook for 5-7 minutes, or until the zucchini is tender but still has a slight bite.
Season with salt and pepper to taste.
Serve hot and enjoy!
Garnish with a dollop of vegan sour cream, a sprinkle of fresh cilantro, or a squeeze of lime juice to brighten the flavors.