You need two large handfuls of baby spinach - check for nasty stalky or wilted bits and then give it a really good wash (nobody likes gritty spinach). Spin dry, and add to a salad bowl with two smaller handfuls of fresh peas (unless you are lucky enough to get young peas which are sweet and tender, you should blanch the peas in boiling, unsalted water and leave to cool). Dress the salad at the last minute with olive oil and lemon juice dressing (see below) and sprinkle crumbled feta cheese over the top.