This escarole and bean soup recipe is the kind of dish you make once and then keep making, because it takes about thirty minutes and tastes like it simmered all afternoon. Cannellini beans turn soft and creamy in a garlicky, parmesan-scented broth, and slightly bitter escarole wilts down into something tender and almost sweet. It's the kind of soup that converts people who insist they don't like leafy greens into people who ask for the recipe.
Dice the onion, celery, and carrot into small, even pieces. Thinly slice the garlic. Cut the escarole in half lengthwise, remove the core, and roughly chop. Wash thoroughly in cold water and spin or pat dry.
Heat olive oil in a large Dutch oven over medium heat. Add the onion, celery, and carrot, and cook for 7-8 minutes until softened. Stir in the garlic and red pepper flakes if using, and cook for 1 minute until fragrant.
Pour in the broth and add the parmesan rind if using. Bring to a gentle simmer, then reduce heat to medium-low. Simmer uncovered for 15 minutes to let the vegetables finish cooking and the rind release its flavor.
Stir in the drained and rinsed cannellini beans and warm through for 5 minutes. For a thicker broth, gently mash a few beans against the side of the pot with a wooden spoon.
Add the chopped escarole in batches, stirring each batch down as it wilts. Simmer for another 5-7 minutes until the escarole is tender but still holds some texture. Remove and discard the parmesan rind.
Season with salt and pepper to taste. Stir in lemon juice if using. Ladle into bowls, top with olive oil and grated Parmesan, and serve with crusty bread.
Notes
Wash the escarole thoroughly, since sand and grit like to hide near the base of the leaves.
Don't skip the parmesan rind if you can get your hands on one; it adds real depth to the broth.
Mash a few beans against the pot for a slightly thicker, creamier texture.
Add the escarole in batches so it wilts down evenly instead of clumping at the top.
Taste before adding salt, since broth and parmesan already bring plenty on their own.
A squeeze of lemon juice right at the end wakes up the whole pot.
Store in an airtight container in the refrigerator for up to 4 days.
Freeze in individual portions for up to 3 months. Thaw overnight before reheating.
Reheat gently on the stovetop over medium-low heat, adding a splash of broth or water since the beans will continue to absorb liquid.
Substitute escarole with curly endive, kale, or Swiss chard if needed.