1) Blanch the French green beans in a large pot of boiling salted water for just 1 1/2 mins. Drain immediately and immerse in a large bowl of ice water to stop the cooking. When they are cool, drain and set aside.
2) Heat the butter and olive oil in a very large saute pan over medium heat and cook the garlic for 1 to 2 mins, tossing occasionally, until lightly browned. Add the French green beans, sprinkle with salt and pepper, and toss together. Reheat the French green beans and serve.