My mom’s butter bean soup is pure comfort food to me. She made it weekly in a slow cooker, and this is my sped-up stovetop version. Add chopped cooked ham to make a hearty main dish if desired, or use vegetable broth to make it vegetarian. For a thicker soup, smash some of the beans using a large spoon.
Heat olive oil in a large stock pot over medium-high heat. Add onion, carrot, and celery, and cook and stir until onion is translucent, about 3 minutes.
Add garlic, marjoram, parsley, and thyme. Cook until fragrant, about 2 minutes more.
Stir in chicken broth, butter beans, vinegar, salt, and pepper, and bring to a boil. Reduce heat and simmer for 30 minutes. Ladle into bowls and serve.