Heat a sauce pan to medium high. Add the oil, let it heat up, then add the onion. Cook the onion until it is fragrant, then add the garlic.
Reduce heat if necessary to cook until transparent, about 5 minutes. Add the water or milk and water.
Stir once or twice and allow it to come to a boil. Add the polenta and quinoa, reduce the heat to medium low.
Stir frequently until the quinoa is cooked and the mixture begins to pull away from the edges of the pot while stirring (about 15 minutes). Remove from heat and add salt and pepper, cheese and or sunflower seeds.
At this point you can spread the polenta onto an oiled sheet pan and allow to cool until firm.
Once cooled you can cut it into pieces and gently crisp it on a skillet in olive oil. You can also cover the cooled polenta with sauce, cheese and other toppings and bake in the oven.
Or you can eat the polenta while it is still soft and hot with whatever toppings or accompaniments appeal to you.