In a saucepan, heat the extra virgin olive oil over medium heat. Add the onions and leeks (if using). Sauté for about 10 minutes, or until the onions begin to caramelize. Make sure to stir occasionally.
Stir in the minced garlic and let it cook for about 30 seconds. Then, add the paprika, cinnamon, and nutmeg, mixing well.
Pour in the tomato passata, and toss in the bay leaf. Stir to combine. Reduce the heat to low, and let it simmer for about 10 minutes.
Incorporate the coconut aminos, apple cider vinegar, mustard, inulin powder, and liquid sweetener (if using). Stir briefly, then turn off the heat. Season the sauce with salt and pepper according to your preference.
For a chunky consistency, leave the sauce as is. You can also blend it to create a smooth paste. Allow the sauce to cool. Once cooled, transfer it to a jar and store in the refrigerator. The sauce will keep well for up to one week.