Add uncooked quinoa to a saucepan and stir for 2 minutes to toast.
Add vegetable broth and bring to boil.
Reduce heat, cover and cook for 15 minutes or until the broth has all been soaked up by the quinoa. Remove from heat and let sit covered for 5 minutes.
While that is cooking, chop onions and mince garlic. And slice your sausage into ½ inch pieces.
Add olive oil to a skillet (we like cast iron for this) over medium heat.
Once hot, add in onions and cook until translucent, about 3-4 minutes. Stirring to make sure it doesn't burn.
Add in garlic and cook for 1 minute.
Add in sliced sausage and Italian seasoning and stir around. Cook for 2 minutes without moving to brown one side of the sausage. Then stir together.
Cook another 2 minutes to brown the other side of the sausage slices and then stir together.
Add in your tomatoes (including juice) and stir again.
Let cook for 5 minutes, stirring occasionally.
Add in spinach and cook for an additional 5 minutes or until spinach has completely wilted.
Add in optional red pepper flakes if desired.
Remove from heat and serve over quinoa.