Cook the potatoes in their skins in a pan of boiling salted water. They will take between 10-12 minutes and should be tender when the point of a knife is inserted. Drain the potatoes and allow to cool.
Meanwhile, place the broad beans in a large pan of boiling salted water. Cook for 3-4 minutes then tip in the peas. Boil for another 2-3 minutes until both the peas and broad beans are tender but still have some texture. Now drain and refresh in icy cold water. Remove the outer skins of the broad beans and discard.
Heat 1 tablespoon of the extra virgin olive oil in a heavy-based saucepan and fry the pancetta until really crispy. Then tip the pancetta with its oil into a large bowl. When the potatoes are cool enough to handle, cut them in half lengthways and add to the bowl. Mix well so that the warm potatoes can absorb some of the delicious pancetta flavours.
In a small food processor or with a hand blender, blend the herb leaves with two tablespoons of the extra virgin olive oil. Then add the lemon juice and whisk in the remaining oil to form an emulsion. Season well with salt and black pepper.
Now throw the peas and the peeled broad beans into the bowl, pour over the dressing and gently mix together. Check the seasoning and serve immediately.