There are two ways to thicken the compote - lemon peel contains pectin, which is a natural thickener. Alternatively, you can use a cornstarch slurry if a fresh lemon isn't available. Warning though - use just a small amount of thickener - we're not making jam! Whisk 1 tsp cornstarch and 1 tsp water until smooth. Pour the slurry into the compote after it has broken down and simmer 1-2 minutes, or until thickened to your desired texture.