1. Peel and dice the potatoes.
Cook them for 15-20 minutes in a pot of boiling water.
2. Slice the onion.
Slice the mushrooms.
Mince the garlic.
Wash and drain the spinach.
3. Sauté the onions in a pan with olive oil.
4. Add the mushrooms, thyme, and garlic. Season with salt and pepper.
Cook for 5 minutes until the mushrooms release their juices.
5. Add the flour and cook for 1 minute.
Add the vegetable broth and stir until the sauce thickens.
6. Add the soy sauce.
7. Drain the potatoes, add the milk, butter, and mash until smooth.
8. Add the spinach and gently stir until wilted.
9. Serve the mashed potatoes and stew sprinkled with thyme.