How to Make It
Put all of the ingredients except the salt and pepper into your blender or food processor, pulse until the peaches and tomatoes have mostly combined, then run on high for 30 seconds. Puree until smooth, when the shallot, garlic and ginger are fully broken down.
Pour the mixture into a heavy-bottomed saucepan and bring to a simmer over medium-low heat. Reduce the heat to low, and cook, stirring frequently, until the mixture reduces by half, or gets to the consistency you prefer. Taste and season with salt and pepper. If you want it spicier, add more red pepper flakes. If too sweet, add another splash of lemon or cider vinegar.
Cool to room temperature, then store in an airtight container in the fridge for up to ten days.