Yogurt Panna Cotta with Sumac Syrup

This panna cotta is more nuanced than standard all-cream panna cotta. Just the right amount of yogurt adds a creamy suppleness and a subtle tang, and lemon zest and thyme lend their perfume. Panna cotta is made in individual portions that often are unmolded for serving, but we simply bring the ramekins to the table, each topped with a spoonful of sweet-tart sumac- and lemon-infused syrup. Sumac is a Middle Eastern spice with a brick-red hue and tangy, citrusy flavor; look for it in well-stocked supermarkets and Middle Eastern grocery stores.