Heat the oil in a large skillet or wok over medium-high heat until shimmering and fragrant.
Add the sliced mushrooms in a single layer and let them sear undisturbed for about 2 minutes, until their edges start to turn golden brown with a slight caramelized crust.
Stir the mushrooms and cook for another 3-4 minutes, allowing them to release their juices and become tender, with some parts darkening further for added flavor.
Add the finely minced garlic and a generous crack of freshly cracked black pepper to the pan; cook for about 30 seconds until the garlic becomes fragrant and slightly golden.
Turn the heat to high and toss everything quickly, letting the pepper coat the mushrooms evenly; cook for another 1-2 minutes until the mushrooms are juicy but not shriveled, and the aroma is pungent and spicy.
Season with the salt, tasting and adjusting as needed, and squeeze a splash of lemon juice over the top for brightness; stir to combine.
Remove from heat and transfer to a serving plate; serve hot, garnished with extra cracked pepper if desired, and enjoy immediately for the best texture and aroma.