Place quinoa, water and bouillon (or salt) into a medium saucepan then place over medium-high heat. Bring liquid to a boil then cover and reduce heat to low. Simmer quinoa for 18–20 minutes until tender. Remove from heat then transfer to a large mixing bowl to cool slightly. Preheat oven to 375 degrees.
Place sliced mushrooms onto cutting board then coarsely chop into roughly ½" pieces or smaller. Place a medium-sized skillet over medium-high heat then add butter or olive oil. Add onion and cook for about 3 minutes until translucent. Add garlic, mushrooms, soy sauce and dried thyme.
Cook 8–10 minutes until the residual liquid from the mushrooms has evaporated and mushrooms are beginning to brown slightly. You will be able to hear the sound in the pan change from a bubbling to a sizzle.
Transfer mushrooms into mixing bowl with quinoa then stir to combine. Let mixture cool slightly before adding beaten eggs, breadcrumbs and Parmesan cheese. Stir to combine then set aside. Coat a baking sheet lightly with cooking spray.
Form patties using about ⅓–½ cup of quinoa mixture. If mixture is too loose or not holding together, add a bit more breadcrumb (or finely grated Parmesan cheese) to bind the mixture a little better. Place patties on prepared baking sheet.
Bake 16–18 minutes or until firm in the center and lightly golden just around the edges. Remove from oven then turn on the broiler. Broil patties to brown them. Let rest for 5 minutes to set and enjoy!
One Last Thing
Soy sauce adds salt and also enhances the mushroom flavor.