Step 1

Rinse and sort beans, removing any that are dried or shriveled.

Step 2

In a medium Dutch oven over medium-high heat, combine beans, water, sage, garlic, and 2 tablespoons olive oil. Bring to a boil, then reduce heat to medium-low to maintain a gentle simmer. Partially cover and simmer, stirring occasionally, until beans are just tender, about 1 hour and 20 minutes. Add more water during cooking if necessary to maintain a soupy consistency.

Step 3

Remove and discard garlic cloves and sage sprig. Add kale, salt, and red pepper flakes to beans, and stir to combine. Cover and simmer until kale is wilted and tender, about 15 minutes.

Step 4

Stir in 1/2 cup oil and grated Parmigiano-Reggiano to finish.