Peel and de-vein the shrimp, if not using already peeled & deveined as I did here.
Heat 1 Tsbp olive oil in a large skillet over medium heat for one minute. Season shrimp with 1 Tbsp taco seasoning, add them in to the pan in a single layer, and cook over medium heat for about two minutes a side until pink and opaque.
While the shrimp is cooking, cut up your onion and mushrooms.
Move the cooked shrimp to a separate bowl. Wipe out the pan and add 1 Tbsp olive oil. Add the diced onion to the pan and saute for two minutes over medium heat.
Stir in the chopped mushrooms, garlic, and 1 Tbsp taco seasoning, then continue to cook over medium heat for another six minutes or until mushrooms have softened, stirring occasionally.
Once the mushrooms are done, remove them to a separate bowl. Quick wipe out the pan; this doesn’t need to be thorough.
Assemble the quesadillas three at a time: Add cheese to one half of a tortilla, then top that with some of the mushroom mixture and 3-4 of the cooked shrimp. Fold each tortilla over, then cook them in batches of three in the same large skillet over medium heat until browned (about one minute per side).
Repeat this process until you’ve used all of the tortillas. Serve with avocado and sour cream.
If you are using larger shrimp, you will want to chop up the cooked shrimp before assembling so that it fits in the quesadillas. Like yours cheesier? Just add more cheese, to your own tastes.
Easy Shrimp & Mushroom Quesadillas from Mashup Mom: