Heat 4 tbsp olive oil in a large skillet and cook the onions gently for 12 to 15 minutes, stirring often, until soft, golden, and caramelized — this is where a lot of the flavor comes from.

Add the garlic and thyme and cook for another minute, until fragrant. Turn up the heat, add the mushrooms, and cook for 12 to 15 minutes, until all the liquid has evaporated and they are golden.

Pour in the white wine and let it bubble for a minute or two, scraping up the tasty bits from the pan. Stir in the dill, season well with salt and pepper, and let the filling cool.

Preheat the oven to 375°F (190°C) and brush a baking dish with oil. Layer about half the filo sheets in the dish, brushing each with oil.

Spread the cooled mushroom filling evenly, then top with the remaining filo sheets, brushing each with oil.

Tuck in the edges, brush the top with plant milk, and score into portions with a sharp knife.

Bake for 35 to 40 minutes, until deeply golden and crisp. Cool slightly before slicing.

To shape it as a spiral, roll the filled filo sheets into long logs and coil them into a round tin; fold chopped toasted walnuts into the filling first for extra crunch.