Italian-Style Cardoon, Bean, and Tomato Soup

• ¼ pound pancetta or prosciutto end
• 1 medium-size onion, finely chopped
• 3

If you’re using pancetta, unroll it. Cut it into ⅛- by 1-inch strips. Over medium heat, cook the pancetta and onion in the olive oil in a 4-quart pot until the onion starts to turn translucent, about 10 minutes.

Peel the cardoon stalks with a vegetable peeler in the same way as for celery. Cut the stalks into ½-inch-thick slices and toss them in the lemon juice in a mixing bowl to preve