Serves 4   Ingredients: For the mash: 6 large baking potatoes 6 Tbsp butter 125ml / ½ cup full cream milk, kept warm   1 medium white onion, diced 1 bunch / 200g swiss chard, roughly chopped   For the mushrooms: 500g mixed cultivated mushrooms 2 Tbsp butter, melted 1 Tbsp lemon juice 2 garlic cloves, grated ± 6 sprigs of fresh thyme ½ tsp chilli flakes   Olive oil Salt and pepper, to taste Micro…