Bring the quinoa and water to a boil in a saucepan over high heat. Reduce heat to medium-low, cover then simmer until the quinoa is tender and the water has been absorbed, about 15 to 20 minutes; set aside.
Meanwhile, heat the vegetable oil in a large saucepan over medium heat. Stir in the onion and cook until the onion softens and turns translucent, about 5 minutes. Add the garlic, chilli powder and cumin; cook and stir 1 minute to release the flavours. Stir in the tomatoes, black beans, green capsicum, red capsicum, zucchini, jalapeno chilli, chilli paste and oregano. Season to taste with salt and pepper. Bring to a simmer over high heat then reduce heat to medium-low, cover then simmer 20 minutes.
After 20 minutes, stir in the reserved quinoa and corn. Cook to reheat the corn for 5 minutes. Remove from the heat then stir in the coriander to serve.
You can find tinned black beans in the organic section of the supermarket, in a health food shop or if you prefer, you can buy them dry at places like bin inn and soak them overnight.