3 tablespoons extra-virgin olive oil
1 small onion, finely chopped
1/3 cup finely diced Serrano ham or prosciutto (2 ounces)
2 large garlic cloves, finely chopped
1 tablespoon fine dry bread crumbs
Two 15-ounce cans butter beans with their liquid
Pinch of dried thyme
1 bay leaf
Large pinch of saffron threads
2 tablespoons water
Freshly ground pepper
3 dozen littleneck clams—scrubbed and shucked, liquor reserved
2 tablespoons finely chopped flat-leaf parsley