In a medium sized pot place the octopus and cover with water. Add the lemon juice and cook the octopus for about 1 hour. Chop the onion into small pieces and crash the garlic. In a frying pan heat the olive oil and cook the onion and garlic. After 1 hour remove the octopus from heat and drain it from water. Chop the octopus into large chunks.
Toss the octopus in the frying pan along with olive oil, sliced cherry tomatos, cooked onions and garlic for 5 minutes. Put 50 ML of wine in the frying pan and cook until the wine evaporates.
