Preheat the Oven: Preheat your oven to 375°F (190°C). This ensures your Sopa Paraguaya will cook to perfection.
Sauté the Onions: In a skillet, sauté with water the julienne-sliced onions until they become slightly translucent. This step should take around 5 minutes. Once done, remove them from the heat and allow them to cool.
Mix the dry Ingredients: In a large bowl, mix well the corn flour (extra fine cornmeal), baking powder, salt and pepper.
Add Wet ingredients: combine the plant-based milk with the dry ingredients. Whisk these ingredients together until they are well incorporated, avoiding lumps.
Add the Onions: Incorporate the sautéed onions into the mixture. Mix everything thoroughly to ensure an even distribution of flavors.
Introduce the Cheese: Now comes the cheesy goodness! Gently mix in the cubed vegan mozzarella cheese. The mixture will look a bit wet, but don't worry; this is what prevents the Sopa Paraguaya from becoming overly dense.
Bake to Perfection: Pour the mixture into your baking dish* and tap it gently to even out the surface. Pop it into the preheated oven and bake for 45-55 minutes** or until it turns a glorious golden brown. You can also check its doneness by inserting a cake tester or toothpick into the center – it should come out clean.
Slice and Savor: Once your Vegan Sopa Paraguaya has cooled, slice it into squares or wedges. It's now ready to be enjoyed!