1pound(16 ounces) dried beans cooked to firm-tender giant white beans see Notes
2tablespoonsolive oildivided
2(~3/4 pound) sweet or hot Italian sausage links, casings removedsee Notes
1large onionchopped
2medium celery stalksdiced
2medium carrotsdiced
1/2poundbutton mushroomschopped
2large garlic clovesminced
1/4cupdry white or red wine
5ouncesbaby spinach or kaleroughly chopped if large pieces
28ouncescrushed tomatoes
Up to 3/4 cup vegetable brothyou may not need this
1/2poundfresh mozzarellacoarsely grated (see Notes)
1/3cupgrated Parmigiano Reggiano cheese
Kosher salt and freshly ground black pepper
2tablespoonsroughly chopped fresh basil for garnishoptional
Instructions
Preheat the oven to 375°F.
In a 4-to-5-quart oven-safe shallow pan (deep sauté pan, braiser, or shallow Dutch oven), heat 1 tablespoon of olive oil over medium heat. Add sausage, breaking up with a wooden spoon as it browns, about 10 minutes. Remove sausage crumbles to a plate. Drain off all but 1 tablespoon of fat.
Add remaining 1 tablespoon of olive oil to the pan. Cook onion, celery, carrots and mushrooms over medium heat until soft, about 10 minutes. Season with Kosher salt and freshly ground black pepper.
Add the garlic, and cook for 1 minute.
Add the wine to scrape up any stuck bits, then simmer until it disappears, 1 to 2 minutes.
Add the spinach or kale, and cook for 1 to 2 minutes, until wilted.
Stir in the tomatoes and bring to a simmer over medium heat.
Stir in the beans and sausage. If the mixture looks too dry or thick (canned tomatoes range quite a bit in juiciness), add up to 3/4 cup broth, 1/4 cup at a time. Simmer the mixture over medium-low heat for about 10 minutes, adding additional Kosher salt and freshly ground black pepper as needed.
If your pan isn’t ovenproof, transfer the mixture to a 3-to-4-quart baking dish.
At this point you can finish it off in the oven, or let it cool, cover it and refrigerate it for up to 2 days. If you refrigerate it, add 15 minutes of baking time to ensure it’s cooked through (internal temperature of 165°F).
Before baking, sprinkle the bean mixture first with the mozzarella and then the Parmigiano Reggiano cheese.
Bake for 10 to 15 minutes, until browned on top (see note).
Finish with fresh basil, if desired.
Notes
I highly recommend using dried beans—they are so much better than canned! If you do use canned beans, be sure to drain them first. This recipe calls for cooking 16 ounces dried beans. That's the equivalent of four 15-ounce cans of beans or 6 cups.
Here’s an easy recipe for Cooking Dried Beans. Since these beans are larger, it took between 1-1/2 to 2 hours for them to cook. You can cook them a day in advance. Drain and refrigerate them until ready for use.
I used California Corona beans from Rancho Gordo (you can also try Royal Corona beans). You’ll see large white beans sold as gigante beans or large white runner beans—found in an Italian or Greek grocery store. Regular-sized white beans will work as well but note that their texture isn’t quite the same.
If you’d like to make this vegetarian, you can leave out the sausage step.
I recommend shredding your own mozzarella rather than buying the pre-shredded cheese. You’ll get a better quality cheese and avoid ingredients added to pre-grated cheese to prevent the cheese from caking.
You can skip the oven step and cook it under the broiler (be sure to adjust your oven rack to a higher position), if you’re short on time and/or want a deeper color.
You can freeze the leftovers in a baking dish. Reheat from frozen at 375°F covered for 45 minutes and uncovered for the last 15 minutes or until heated through (internal temperature of 165°F). If your dish is ceramic, I recommend leaving it on the counter for 15 minutes before placing it in the oven to avoid too much of a change in temperature shock.