Simmer the sloppy joe mixture: Simmer the mixture for a few minutes to combine flavors. Taste and adjust seasonings to your liking. It will probably need a pinch of salt and pepper. Add an extra tablespoon of brown sugar to make it sweeter or a dash of apple cider vinegar to make it a bit more tart.
Make the sandwiches: Toast your buns and add thinly sliced red onions to the bottom half of the bun. Top with 1/3 to 1/2 cup of the vegan sloppy joe filling. Add pickles and eat immediately.
LEFTOVERS: Leftover sloppy joe mixture will store well in the fridge for a few days or it can be frozen in an airtight container for up to 3 months. Reheat sloppy joe mixture gently over the stove with a splash of water. Spoon it atop a baked sweet potato for lunch the next day if desired!
Once I got them to try a tiny bite, they were all in on it.