Creamy Polenta with Mushrooms and Gremolata from Life's Too Short to Stuff a Mushroom by Prue Leith

Ingredients

• 1 litre/35 fl oz/4⅓ cups vegetable stock (bouillon)
• 500 ml/17 fl oz/generous 2 cups whole milk
• 250 g/9 oz/1⅔ cups instant fine polenta (cornmeal)
• 100 g/3½ oz strong Cheddar, grated
• 75 g/2½ oz Parmesan, finely grated
• 50 g/1¾ oz butter
• 3 thyme sprigs, leaves picked and chopped
• 1 tbsp chopped tarragon
• salt
• black pepper
• 2 tbsp finely chopped flat-leaf parsley
• zest of 1 lemon
• 3 tbsp olive oil
• 1 garlic clove, crushed
• 250 g/9 oz chestnut (cremini) mushrooms, cleaned and sliced
• 2 tbsp olive oil
• 100 g/3½ oz shiitake mushrooms, torn in half