This was the solution to the "broadbean problem" in the end. Broadbeans grew particularly well in the allotment and their weird green colour is really interesting!
Blanch the broadbeans by dropping them in boiling water for about 2 minutes, then in cold water before shelling them (a little painful but worth it). Be warned though: it takes quite a lot of broadbeans to get enough.
Dice an onion and fry. Add some pre-cooked, sliced potatoes and season with salt and pepper. (For baby portions leave the salt.)
Whisk 4 to 6 eggs until well mixed and even, add a little melted butter to prevent the frittata from sticking.
Add the egg mix, broadbeans and a handful of feta to the pan and cook (covered) on a low heat until the top starts to set. once it reaches this stage remove from the heat and put the pan under a low temperature grill to finish cooking.
The end result is healthy and delicious.