Heat oil in a 5-quart pot over medium heat. Cook onion, carrots and celery for 6 minutes.
Mash 1/2 cup of the butter beans with 1/2 cup of the measured broth until mostly smooth. Stir the mash into the pot with remaining beans, broth, ham, thyme and pepper.
Bring to a simmer and cook partly covered for 12 to 15 minutes until carrots are tender and the ham reaches 165°F.
Stir gently from the bottom, keeping most large beans whole. Add Dijon and cider vinegar off the heat.
Divide among 6 bowls with ham, beans and enough broth in every serving.