Bring a large pot of salted water to a boil. Add the beans and cook for approximately 3 minutes. Drain the beans and put them into a large bowl filled with ice cold water. Drain again. Set aside.

Add the walnuts to a food processor and grind them into a course ground.

In a large pan over medium-low heat, add the olive oil and garlic. Cook for 2 minutes, stirring. Add the ground walnuts and thyme to the pan and cook for 1 minute, stirring. Add the beans to the pan, season with salt and pepper, and continue cooking for 5 minutes longer, stirring.

Transfer the beans to a serving dish. Serve immediately.