02
Make it
Heat the oven to 425°F. Use a vegetable peeler to shave several long, wide strips of peel from the lemon, taking only the yellow zest and avoiding the bitter white pith. Juice the lemon and set both the peel and juice aside.
Place the chopped bacon in a large oven-safe skillet over medium heat. Cook for 6 to 8 minutes, stirring occasionally, until the fat has rendered and the bacon is beginning to brown but is not yet completely crisp.
Add the butter and sliced sweet onion to the bacon and rendered fat. Season lightly with salt and generously with black pepper. Cook for 6 to 8 minutes, until the onion is partially softened and beginning to caramelize.
Scatter about half of the freshly grated Parmesan over the partially cooked onions and bacon. Add the halved Brussels sprouts, wide lemon peels, and about 2 tablespoons of the fresh lemon juice. Toss everything thoroughly in the butter, bacon fat, melted cheese, and onions. Taste before adding more salt because the bacon and Parmesan are already salty.
Spread the mixture into an even layer, arranging as many Brussels sprouts cut-side down against the skillet as possible. Grate or scatter the remaining Parmesan generously over the top.
Transfer the uncovered skillet to the oven and roast without stirring for 20 to 25 minutes, until the sprouts are tender, the Parmesan is deeply golden, and the bottom has formed a crisp, caramelized crust. Give it a few additional minutes if needed to achieve that dark, crunchy underside.
Let the skillet rest for 5 minutes, then use a sturdy spoon or spatula to lift each serving from underneath so everyone gets plenty of the crispy bacon, onion, and Parmesan bottom.
The crispy-bottom secret
Do not stir the sprouts once they go into the oven. Keeping the cut sides pressed against the hot skillet is what creates the amazing crispy bottom—and make sure every serving gets some of it.

