Heat the oil in a wide saucepan and cook the onion until it begins to brown.
Add the garlic, thyme, oregano, and mushrooms.
Cook, stirring frequently, until the mushrooms give up their juices, 3 to 4 minutes.
Add the tomato, purslane, salt, pepper, and 2 tablespoons of water.
Bring to a boil; then reduce the heat to low, cover, and simmer until the vegetables are tender, 10 to 12 minutes.