In a reusable container, whisk together the ingredients for the lamb marinade. Add the lamb and toss to combine. Refrigerate, covered, for 4 to 24 hours.
1/3 cup olive oil, 2 tablespoons lemon juice, 2 tablespoons red wine vinegar, 2 cloves garlic, 1 tablespoon fresh rosemary, 1 tablespoon fresh thyme, 1 teaspoon kosher salt, 1/2 teaspoon crushed red pepper flakes, 1/4 teaspoon black pepper