You could just buy a 500g packet of haricot beans and sow some for growing and eat the rest . You have to check that they are gm free , but nearly all dried beans sold for food that i have sown , have grown , you just don't have a named variety .
The type they use in bb i think are grown in europe , but they will grow here in uk but not on an agricultural scale .
Just a matter of avoiding the frost i think , but i grew them ok from a packet of dried haricot beans , and the beans i kept from the harvested crop grew fine and true to type , but one year cows got in and ate the lot .
When i made bb with them i used passata with herbs and garlic added .