Beans in mustard sauce, Apicius 5.6.3
from Cooking Apicius: Roman Recipes for Today by Sally Grainger

It is not clear what type of bean the ‘Baian bean’ specified in the original manuscript might have been. The recipe works best with a broad (fava) or butter bean, but cannellini, haricot, black-eyed beans and other sorts may also be used with profit. The flavour is rich, intense and immediate from the pine kernels and cumin, and given a sweet and sour richness by the honey and vinegar. Your guests will not want to eat much at once. I have added a little wine to the recipe in order to make the sauce thinner than the original allows. You will need a mortar for this dish, or a small food processor: the large bowls attached to a standard machine will not be able to purée the pine kernels effectively.

150 g dried broad beans or butter beans
60 g pine kernels
1 tbsp honey
20 g whole grain mustard
1 tsp chopped fresh or dried rue
2 tsp cumin
2 tbsp vinegar
50 ml white wine
freshly ground black pepper

Soak the beans overnight or for at least 4 hours. Boil in fresh salted water until they are soft but still hold their shape. Drain, refresh and keep to one side. If you are preparing the sauce in a mortar, pound the pine kernels until you have a paste. Alternatively, place them in a small processor and grind as fine as possible. Add the honey, mustard, rue, roasted and ground cumin and the vinegar and blend into a smooth emulsion. Flush out the bowl or mortar with the wine, pour into a saucepan with all the other sauce components and bring to a simmer. Stir into the hot beans and serve sprinkled with freshly ground black pepper.