Prepare the Brussels sprouts by trimming off the tough stem ends and removing any discolored outer leaves. Cut each sprout in half lengthwise through the stem. (For larger sprouts, you might want to quarter them for more even cooking.)
Heat your skillet over medium-high heat until it’s properly hot. This is crucial for achieving caramelization rather than steaming the sprouts.
Add the oil or butter to the hot pan and swirl to coat the surface evenly. Wait until the fat is shimmering but not smoking.
Place the Brussels sprouts cut-side down in a single layer in the hot pan. Don’t overcrowd the pan – cook in batches if necessary. Let them cook undisturbed for 3-4 minutes until the bottoms develop a deep golden-brown color.
Toss or stir the sprouts and continue cooking for another 3-4 minutes, stirring occasionally, until they’re tender-crisp when pierced with a fork.
Add the minced garlic to the pan and cook for just 30 seconds until fragrant, being careful not to let it burn.
Season with salt and pepper to taste, then remove the pan from heat.
Sprinkle with fresh lemon juice and toss to combine. Add any optional ingredients like Parmesan cheese, red pepper flakes, or balsamic vinegar at this stage.
Serve immediately while hot and crispy for the best flavor and texture.