Coat the bottom of large sauté pan (preferably cast iron), with grapeseed oil and place it over medium-high heat.
Add the peppers. (You should immediately hear them sizzle -- if you don't, the pan isn't hot enough yet. Wait for the sizzle!)
Sauté the peppers until they are nicely charred -- each pepper will be about 50% green and 50% charred. They should be flipped/stirred every so often, and the total cooking time will be about 10 minutes.
Season generously with salt and pepper and serve hot or warm.