If you are using frozen peas and broad beans, defrost them by running them under cold water for 4-5 minutes.
Peel the shallot and then dice it as finely as you can.
Zest the lemon.
Pop the broad beans out of their leathery skins by making a small hole with your fingernails, then squeeze out the bean.
Snap the woody ends off the asparagus and discard them, then thinly slice the asparagus with either a mandolin or a vegetable peeler.
Heat the olive oil in a medium frying pan (24cm or 10") over a medium heat. When the oil is hot, add the shallot and cook, stirring constantly, for 2 minutes.
Remove the pan from the heat and add the peas and broad beans, and toss in the oil for a minute.
Add the salt, pepper, lemon zest, shaved asparagus and samphire, toss to coat in the oil and gently warm. The ingredients should not get too hot at any time.
Squeeze in the juice of half of the lemon, have a taste and add more salt, pepper and lemon juice if required before serving.