In a Medium pot, heat oil over medium high heat, add diced onions. Saute until tender, stirring often, about 4 – 5 minutes. Turn heat to medium, add garlic, and mushrooms.
Saute until mushrooms are just tender, about 3-4 more minutes. Add tomatoes, sugar, salt and pepper. Saute until tomatoes begin to melt, about 2-3 minutes.
Add stock and soy sauce (optional). Add tofu and tamarind paste ( or lime juice). Bring to a boil, and let simmer for 3-4 minutes. Taste for balance. Add salt to taste.
Serve in a bowls with chopped cilantro and chives and chili flakes.
Serves 2 for dinner or 4 as a starter.