Cheesy broiled sheet pan pasta with Brussels sprouts and pancetta

Bring a pot of water to a boil for the pasta with a big pinch of salt.

For the topping, zest the lemon, grate a pile of pecorino and pick the thyme leaves.

Slice the red chili thin, stopping near the seedy top; smash and peel the garlic.

Chop the zest, cheese, thyme, chili and garlic into each other until fine.

Mix in a bowl with a roughly equal quantity of panko until well blended.

Grate the mozzarella and set aside. Cut the stem end off each Brussels sprout and quarter them.

Spread the diced pancetta on a sheet pan, put it into a cold oven and turn on the broiler so the fat renders slowly before the meat browns.

Drop the pasta into the boiling water.

When the pancetta is almost done, add the Brussels sprouts and thinly sliced carrots, salt enough for the vegetables, and toss in the rendered fat.

Spread in an even layer and return under the broiler.

Drain the pasta after 10 minutes of a 13-minute package time; shake it now and then so it does not stick.

After about five minutes, with the sprouts halfway done, add the diced shallots and the fennel seeds, toss to coat in the fat and return under the broiler.

When the vegetables are almost done, turn the broiler off. Toss in about a third of the mozzarella and all of the pasta, then level smooth.

Dollop the ricotta over and nestle it in.

Scatter the remaining mozzarella and the breadcrumb topping everywhere except on the ricotta, then drizzle with olive oil.

Broil, watching carefully; it needs only a few minutes before things start to burn. Without a broiler, use the oven as hot as it goes.

Squeeze the lemon juice over and serve from the pan.