This hearty, comforting soup transforms humble white beans and wheat berries into an irresistible indulgence. The secret lies in the Parmesan rinds, which melt into the broth over hours, infusing it with a deep, rich, cheesy flavour. Packed with fibre from the beans and grains, this slow-cooked wonder is worth the wait.
dry, soaked overnight and drained
hard rinds cut off and reserved, the rest grated for serving
large
fresh
dry
bunch, leaves chopped
large, juiced
Finely chop the onion and the fennel bulb (reserving the roughly chopped fennel fronds). Slice the celery sticks into 1 cm thick pieces and roughly chop the garlic cloves. Grate the Parmesan, setting aside the hard rinds.
Place the soaked and drained cannellini beans into a 5- to 8-litre slow cooker. Season generously with kosher salt and black pepper. Add the reserved Parmesan rinds and the wheat berries.
Warm the extra virgin olive oil in a large skillet over medium-high heat. Add the chopped onion, season generously with salt, and cook, stirring occasionally, until softened, about 5 minutes. Add the chopped fennel bulb and continue to cook, stirring often, until the fennel is softened and the onion is lightly browned, about 5 more minutes.
Add the celery and chopped garlic to the skillet and cook, stirring, until just softened, about 1 minute. Stir in the fennel seed and red pepper flake, cooking constantly until combined and fragrant, about 1 minute. Add the rosemary sprigs and the dry white wine. Let the wine bubble until the pan is almost dry, about 2 minutes.
Scrape the mixture from the skillet into the slow cooker. Add the chicken stock. Season the stock with 0.5 teaspoon of salt if using low-sodium stock, or 1 teaspoon if using unsalted homemade stock. Stir to combine all ingredients. Cook on the low setting for 10 hours, or until the wheat berries are tender and the beans are creamy.
Before serving, remove and discard the rosemary sprigs. Stir in the chopped parsley, the juice of the lemon, and the reserved fennel fronds. Taste the soup and add extra salt and pepper if needed. Serve immediately in bowls, topped generously with the grated Parmesan.
Sautéing the vegetables (the aromatics) in a skillet before adding them to the slow cooker is crucial for developing a deep, caramelised flavour base. Do not skip this step unless absolutely necessary.
If you cannot find wheat berries, you can substitute with whole grain farro or spelt, but monitor the cooking time as they may soften faster than the wheat berries.
The soup can hold well on the 'warm' setting for an additional 1 to 2 hours after cooking is complete.