Step 1
In a Dutch oven, heat the oil, two turns of the pan, over medium-high. Add the bacon and cook, stirring often, until the fat renders, 2 to 3 minutes. Add the leeks, onion, carrots, celery, garlic, bay leaf, and herb bundle; season with salt and pepper. Cook until the vegetables soften, about 8 minutes. Add the escarole and kale. Cook, stirring, until the greens wilt, about 2 minutes. Stir in the tomatoes, passata, stock, and beans. Bring to a boil, then reduce the heat to medium and simmer until the flavors meld, 15 to 20 minutes. Discard the herb bundle before serving.