Place the olives in a bowl with the lemon zest.

In a small saucepan over medium high heat, combine the olive oil, whole garlic cloves, crushed red pepper flakes, sliced shallot and thyme. Cook until the garlic starts to sizzle, about 1-2 minutes, then reduce heat to low and continue to cook for 20 minutes. Remove pan from heat, add the crushed olives and lemon zest and let steep for 1 hour. Pour oil over the feta at least 20 minutes before serving. (can be combined to marinate for up to 48 hours)