Put a large pan of salted water on to boil. Scrub the Jersey Royals and chop them into bite-sized chunks. Pop the broad beans out of their pods.
When the water is boiling, carefully add the potatoes to the pan. Simmer for 12 mins till you can nearly pierce them with a knife.
Add the broad beans to the pan and cook for a further 3 mins. The potatoes should be tender. Drain and leave in the colander to steam dry (see our tip on double podding the broad beans).
While the potatoes simmer, peel and finely slice the shallots. Add 1 tbsp olive oil to a frying pan set on a medium heat. Add the shallots with a pinch of salt. Fry for 5-6 mins till crispy. Tip onto a plate lined with kitchen paper to drain.
Meanwhile, finely chop the mint leaves and finely slice the sorrel. Zest the lemon into a large mixing bowl and squeeze in the juice from 1 half. Add the crème fraîche, season and stir to make a dressing.
Tip the broad beans and potatoes into the bowl with the crème fraîche dressing. Add half the mint and sorrel. Toss and pop in a salad bowl. Scatter over the remaining herbs and the crispy shallots. Serve with the spare lemon half, cut into wedges.