1. Cook the brown rice a few more minutes than recommended in the instructions, making it slightly over-cooked (this will help bind the dough).
2. Peel and chop the onion. Wash and cut the mushrooms. Sauté in a pan with a dash of olive oil until the onion becomes translucent.
3. Wash the cooked pulses in abundant water, drain and set aside.
4. Put the pulses, rice and fried onion in a bowl and mash with a fork. Add the beaten egg whites and mix until homogenous. Add the thyme leaves and season with pepper. Add the garlic powder and the nutritional yeast (optional) and mix.
5. Place the dough in the fridge for one hour. Shape into a patties with the help of your hands or a cookie cutter.
6. Lightly brown the burgers in a pan with a few drops of olive oil at medium heat. Serve with sautéed vegetables and romesco sauce.