Slice a hole in the sweet potato and heat in the microwave for ~ 5 minutes or until softened. Set aside to cool.
Place black beans in a strainer and rinse thoroughly. Set to the side to dry.
Slice the bell pepper into smaller pieces.
Place 3 tbsp water and chia seeds in a bowl off to the side. The chia seeds will gelatinize, forming a “chia egg.”
Once the sweet potato is cooled, remove the skin. Add all ingredients except for the rolled oats and “chia egg” to a food processor. Pulse mixture for several seconds to mix. You will need to scrap the sides of the food processor several times throughout the process. Blend until the ingredients have mixed together, but it is not completely homogeneous. You want the mixture to be somewhat clumpy to help it form into patties.
Add the 1/4 cup rolled oats to the food processor. Pulse for a few seconds to disperse the oats throughout the mixture, but not fully blend.
Place the contents of the food processor into a bowl. Add the chia egg and the remaining 1/4 cup rolled oats. Mix the contents of the bowl. Form the mixture into veggie patties (it will make ~6).
Cook veggie burgers on a baking dish over parchment paper at 375 degrees for ~20 minutes.