Preheat the oven 350°F a line a rimmed baking sheet with parchment paper.
In a skillet heat olive oil and add diced onion cooking for 3-4 minutes until translucent.
Add sun-dried tomatoes and shiitake mushrooms. Cook for additional 3-4 minutes
Turn off the heat and add the garlic. Allow the garlic to cook for about 30 seconds then remove the skillet from the heat.
To the bowl the of a food processor, pulse stale bread into crumbs. Remove the crumbs from the bowl and set aside.
Next, add the tomato and mushroom mixture and pulse a few times before adding 1 cup of cooked and cooled quinoa. Then pulse a few more times.
Add the breadcrumbs and the rest of quinoa pulsing until just combined.
The mixture will be slightly sticky. Roll about 2 tbsp of the quinoa mixture into a ball and place on the prepared baking sheet. Continue rolling the mixture into balls until all the mixture is used.
Bake the meatballs for 30 minutes, turning half way through baking. Serve with your favorite pasta sauce and pasta. Top with fresh herbs and vegan parmesan cheese next to a slice of warm French bread.