Add the garlic and cook 1 minute more. Raise the heat to medium-high and add the tomatoes, chopped thyme, lemon zest, and half of the olives, capers, and peppers. Simmer briskly, stirring, for about 5 minutes to evaporate some of the liquid. Reduce the heat to medium-low, stir in 1 cup water and simmer for 15 minutes. Taste and season with salt. Cool.