Slice the oyster/button mushrooms but make sure they are not too thin, so they don't disappear in the final dish. Cut the chard, separating the leafy parts from the tougher stems to cook the stems a bit earlier than the leaves.
Also, cut the onion, chop the garlic and chop any fresh herbs like parsley if you are using them.
Cover the mushroom slices with a tablespoon of flour and season with salt and pepper. Stir thoroughly to ensure they are evenly coated on all sides.
In the next step, roast the mushrooms on medium to high heat in some oil in a pan. Cook for about 6-7 minutes until they develop crispy bits. Then, remove them from the pan and set them aside.
In the same pan, toss in the thicker white chard stems and cook them for 3-4 minutes until they soften and slightly brown.
Add the onions, garlic and spices and keep stirring. The spices might dry the vegetables a bit, so ensure nothing burns by keeping a close eye on them. Deglaze everything with white wine.
Next, add the cup of unsweetened plain milk, tomato puree and the chopped tomatoes. Stir them in and turn up the heat slightly until the mixture starts to bubble. Also add the veggie stock powder to let it simmer away together.
Lastly, add the green parts of the chard, the oyster mushrooms and the chopped herbs. Cook for another 5 minutes until the chard softens. Remove from the stove and let it rest for a few minutes. Serve with rice or quinoa and drizzle with lemon if desired. Enjoy!