Gently wipe the portobello mushrooms clean with a damp paper towel and remove the stems. 2.
Heat the vegan butter or olive oil in a large skillet over medium-high heat until it shimmers. 3.
Place the mushroom caps in the hot pan, gill-side up, ensuring they don't overcrowd the pan. 4.
Sprinkle generously with salt and pepper. 5.
Sauté for 4 minutes, until the mushrooms have released their moisture and the bottoms are nicely browned. 6.
Flip the mushrooms and cook for another 2-3 minutes, until tender and heated through. 7.
Serve immediately as a main, in a burger, or sliced over a salad.