In a frying pan, heat the oil on low heat and gently fry the mushrooms for about 2-3 minutes (do not overcook!).
Sprinkle in the garlic and basil, then toss the mixture for a minute or two so that mushrooms are well coated.
Add the diced tomato, lemon juice, salt, pepper and water.
Stir together and cook until the tomato softens.
Remove from the heat and let cool at room temperature for about 1-2 hours (so the flavors blend together).
Garnish with chopped herbs.