Pork Loin in the Style of Porchetta

In a 10- to 12-inch saute pan, heat 1/4 cup of the olive oil over medium-high heat until smoking. Add the sliced onion and fennel and saute until softened and lightly browned, 7 to 8 minutes.

Add the ground pork or sweet Italian sausage, fennel seeds, rosemary, garlic, and 1 to 2 tablespoons pepper (depending on your taste), and cook, stirring occasionally, until the pork is no longer pink, about 10 minutes. Transfer to a bowl and let cool.

Preheat the oven to 425°F (220°C).

Meanwhile, place the pork loin flat on your work surface and sprinkle with salt and pepper.

Add all but 1 tablespoon of the fennel fronds, the bread crumbs, and eggs to the pork mixture and mix gently. Spread the mixture over the pork loin. Roll it up, starting from a long side, like a jelly roll, and tie with butcher's twine.☞ TESTER TIP: To prevent the filling from squishing out the ends, poke several long skewers through the porchetta near both ends to help close them before tying with twine.

Scatter the red onions in a roasting pan and place the pork loin on top. Drizzle the pork and onions with olive oil and rub to coat. Roast for 75 minutes, or until the internal temperature is 135°F (57°C).

Remove the pork loin from the oven and let rest for 10 minutes.

Slice the pork loin into 1-inch-thick pieces. Serve the pork drizzled with the remaining 1/4 cup olive oil and a good squeeze of lemon, garnished with the reserved fennel fronds, and with the onions on the side. (You can toss any leftovers in the fridge and slice them thin for the king of sandwiches the next day.)