Neil Perry's mushroom risotto cakes with aioli

Ingredients

• 10g dried porcini mushrooms
• 750ml vegetable or chicken stock
• 30ml extra virgin olive oil
• 1 small onion, finely chopped
• 2 garlic cloves, finely chopped
• sea salt
• 220g arborio rice
• 80ml dry white wine
• 30g parmesan, freshly grated
• 1 egg yolk, lightly whisked
• 140g fresh breadcrumbs
• olive oil, for shallow-frying
• mixed salad leaves, to serve
• 1 cup aioli
• 1 fresh lemon, quartered