Heat oil over medium-high heat in a skillet with a lid. Once oil is hot, add the corn and yellow pepper. Season with salt and fresh-ground pepper, then cook, stirring occasionally, until veggies soften and corn begins to brown (10 minutes or so).
Add the quinoa and stir. Continue cooking for a couple minutes. When quinoa starts popping and getting toasted, add the stock or water and bring to a boil. Stir one more time, then cover and reduce heat to low. Cook covered and undisturbed for 15 minutes.
Uncover and check quinoa for doneness. If the grains are still hard, make sure there's still enough liquid to keep the bottom of the pan moist, cover and cook for another 5 minutes.
When the quinoa is ready, remove from the heat and taste for seasonings. Add more salt and pepper if needed, then add the chopped herbs for garnish. This can be served warm, or it can be allowed to cool to room temperature before serving.