If your diet plan allows a higher carb intake but you don't want the gluten that comes with a normal burger bun, a black bean burger is a great alternative.
In a bowl, mash the beans to break apart.
Blend the red pepper, onion, and garlic in a food processor until tiny chunks are formed. Stir this into the bean mixture.
Next, add in the egg, spices, and avocado. Stir together well, then mix in the oats.
Form into four large patties. Place on a preheated grill, brushed with a little olive oil, then grill for about 8 minutes per side.
Serve with a little added avocado on top, if desired.