Heat a large frying pan on medium heat. Add the tsp of oil, or a few sprays of fry spray. Add the roughly chopped pepper, sliced mushrooms and garlic and cook for 2-3 minutes. Add the spices, stir to evenly coat the vegetables, then cook for a further 3-5 minutes until vegetables have softened and spices are fragrant.
Add the contents of the pan and all of the other remaining ingredients to a food processor and pulse until all of the ingredients are thoroughly combined but still have some texture. The mix should be slightly sticky but not overly wet. If it’s too wet, add some more breadcrumbs and pulse again. If you want to hide the vegetables, process until completely smooth.
Divide the mix into equal servings and shape into burgers with your hands. Place on a baking tray in the centre of the oven and cook for 30 minutes. They should be firm on the outside, softer in the centre and hot all the way through when they’re ready.