In a medium pot, bring the 4 cups of broth or water to a boil.
Slowly pour in the polenta, stirring at the same time to prevent clumps.
Turn the heat down to low so the bottom doesn't burn, and keep stirring every 2 to 3 minutes, scraping the bottom of the pot every time.
You should achieve doneness in about 30 minutes. Taste to check whether the result is as smooth as you like it. If it's still gritty under the teeth, you can cook for a little longer, adding more water. It should not be completely runny, but still fall off a spoon.
Add the nutritional yeast, garlic, fresh pepper, and vegan butter or olive oil (if desired). Stir well. Taste and adjust seasoning, adding a little salt if required.
Add more ingredients if you wish (see notes for variations).
You can enjoy your polenta immediately. Or you can spread the polenta onto a sheet of parchment paper or silicone baking mat, about 1/2 inch thick, and let it cool off, then cut into squares that you can then grill in the pan (now or later). Or you can pour the hot polenta into a small loaf pan, let it cool and solidify, and then refrigerate or freeze... with the prospect of slicing and grilling later. Endless options!