First, make the dressing by mixing the olive oil, dijon mustard, salt, pepper, lemon juice and garlic in a small bowl. Set aside.
Heat the olive oil in a pan over medium heat. Fry the shallots until golden and somewhat crispy. Remove from the pan and onto a plate lined with a paper towel to absorb the excess oil.
Bring a pot of water to boil and add 1 tsp salt to the water. Add the green beans to the boiling water and cook for 8 minutes (this is called blanching).
Meanwhile, fill a large bowl with water and ice and set it aside. After 8 minutes, using a slotted spoon, take the green beans out of the boiling water and place them in the ice water. Let the green beans be in the ice water for 5 minutes, then drain and dry them.
Place the green beans in a shallow bowl or a platter and top with fried shallots, feta, tomatoes, walnuts, olives, mint and green onion. Drizzle with the dijon dressing and serve.
