Preheat oven to 350 degrees F.
Spray 8" baking dish with cooking spray
In large skillet, heat 2 tbsp of olive oil over medium-high heat.
Add onions and cook until translucent, about 5-7 minutes.
Add garlic and cook another minute.
Add flour, mixing to combine and cook one minute, stirring often.
Slowly (I mean it - slowwwwwly) add the milk, stirring constantly.
Once all of the milk is added, let it cook 3-4 minutes over medium heat, stirring often.
Add 1 1/2 cups of cheese, stirring until melted.
Stir in broccoli and quinoa.
Pour into prepared baking dish.
Top with remaining cheese.
Bake in preheated oven for 15 minutes, until cheese is melted on top and mixture is bubbling.
Serve and enjoy!