"There's a lat of wiggle room in this hearty crowd-pleaser. You can cook the sausage and bean mixture a day or two in advance (just allow for extra oven time since it will be cold). If you have an ovenproof pan, such as a cast-iron skillet, you can also use that for the entire recipe. Folding some spinach into the mixture before baking is an easy way to add some color and vegetables, but you can skip it or use other leafy greens, such as Swiss chard, escarole, or broccoli rabe (sturdier ones will need to be blanched first). The gratin also reheats well."

Preheat the oven to 425 °F, with a rack in the middle position. In a small bowl, combine the panko and butter, season with salt, and set aside.

In a large skillet, heat the oil over high heat until it shimmers. Add the sausages and cook, stirring often and breaking up the meat, until browned, about 4 min­utes. Leaving as much oil in the pan as possible, transfer the sausage to a medium bowl and set aside.

Reduce the heat to medium-low, add the onions and garlic and cook, stirring occasionally, until the onions are softened, about 8 minutes. Add the tomato paste and thyme and stir for about 30 seconds. Add the wine and briskly simmer,

scraping up any caramelized bits from the bottom of the pan, until almost evaporated, about 2 minutes.

Add the broth and bring to a simmer, then add the beans, cooked sausage, and any juices. Season with salt and pepper and simmer, stirring occasionally, until heated through and some of the liquid is absorbed, about 5 minutes. The mixture should be wet, but not drowning in liquid. Off the heat, stir in the spinach (if using). Check the seasonings, then transfer the mixture to a 3-quart baking or gratin dish.

Top evenly with the panko mixture and bake until bubbling and the top is golden brown, about 15 minutes. Let rest for 5 to 10 minutes before serving.