1 tsp arrowroot or cornflour, mixed with 1 tsp cold water
Swiss chard or other seasonal greens, to serve
Mix 1 tbsp oil, 1 tbsp miso, the garlic and chopped sage; brush over the mushrooms. Boil the potatoes in a covered pan of salted water for 10-12 minutes, until very soft. Drain and mash to a smooth purée. Stir in the cream alternative; season. Preheat the oven to 140˚C, gas mark 1.
Meanwhile, fry the sage leaves in 1 tbsp oil for 2-3 minutes until crisp. Drain on kitchen paper; keep warm. Wash out the pan, then boil the stock, the remaining 1 tbsp miso and the maple syrup for 10 minutes, until reduced to 175ml. Set aside.
Heat the remaining 1 tsp oil in an ovenproof non-stick frying pan. Fry the mushrooms, stalk-side down, on a medium-high heat for 2 minutes, pressing now and again with a fish slice, until deep golden. Turn, cook for 2 minutes, then put in the oven for 10 minutes. Reheat the gravy, add any mushroom juices and whisk in the arrowroot or cornflour. Simmer until glossy and a little thick. Season and serve with the veg, sage and mushrooms.
Arrowroot is really useful for vegetarian or vegan gravies, as it adds body without making the gravy cloudy. Avoid re-boiling once it has thickened.