Holding the corn upright on the chopping board, carefully run a knife down the sides to cut off the kernels. Put the kernels into a blender with 125ml water and blitz to a paste.
Peel the onion and finely slice along with the coriander stalks, reserving the leaves. Heat 1 tablespoon of oil in a medium non-stick pan and fry the onion and coriander over a medium-low heat for 10 to 15 minutes, or until softened.
Deseed the chillies and peel the garlic, then finely chop both. Add to the pan with the cumin and fry for 1 to 2 minutes.
Add the corn paste and cook gently for 5 to 10 minutes, or until just simmering, but not coloured. Season well with sea salt and black pepper, spoon the mixture into a bowl and set aside to cool.
Blanch the broad beans in boiling water for 2 minutes, then drain and rinse under cold water. Set aside to cool, then remove the outer skins, if you like, and discard.
Cook the quinoa according to the packet instructions Drizzle with extra virgin olive oil while it’s still hot, then finely grate over the lime zest and squeeze in the juice. Add the beans, toss well and leave to cool.
Finely chop the coriander leaves, reserving a few for garnish, and stir through the quinoa along with the cooled corn mixture. Spread over a large serving plate.
Place the whole block of feta, brine and all, into a small non-stick frying pan. Drizzle with olive oil and a little chilli sauce, if using. Bring to the boil, then cook over a high heat until the feta is lightly golden. Carefully turn over and cook for 2 more minutes.
Break up the feta with a fork, add to the salad and drizzle over any pan juices. Scatter over the reserved coriander and bring to the table.