Open a can of crushed pineapple. Drain the pineapple juice from the can and measure out 1/3 cup.
Pour the cornstarch and 2 tbsp of the pineapple juice into a small saucepan. Stir until combined and no lumps remain. Slowly pour the rest of the pineapple juice into the pan while stirring constantly.
Mix in the remaining ingredients. Heat pan on medium low heat. Stir the mixture approximately every 30 seconds. Cook for approximately 5 minutes until sauce has thickened. Taste the sauce, and add in more vinegar, sugar and/or soy/fish sauce as needed.
Store in a container in the fridge for up to 5 days.
Notes
Makes approximately 8 servings (1 tbsp per serving).
It is important to mix the cornstarch into the pineapple juice otherwise your sauce will be lumpy.
*The soy sauce or fish sauce adds a savoury flavour to balance out the sweet and sour. Soy sauce contains gluten but is low FODMAP in serving sizes of 2 tbsp or less. If you have celiac disease and need to strictly avoid gluten, use 1/2 tsp of fish sauce instead of soy sauce.*
If you wanted to make this more of a sweet spicy sauce then you could add in some red pepper flakes or chopped chilli. Note: some individuals with IBS find that spicy food can be a symptom trigger unrelated to FODMAPs. Personally, I need to avoid spicy foods.
I tested freezing this sauce and it worked pretty well! The texture and colour changed slightly after defrosting but still tasted good. I recommend putting the sauce you want to freeze in a ziploc bag, closing the bag, and then spreading the sauce out thin so the bag is pretty flat. When you want to eat some sauce you can break off a piece and leave it on the counter to defrost. I have not tried defrosting it in the microwave yet.