Peel and clean the shrimp. Slice in half length-wise. Using a paper towel, dry off the shrimp.
Put 1 teaspoon oil into a non-stick skillet and cook the mushrooms on medium heat for about 5 to 6 minutes. Remove mushrooms and set aside. Wipe down the pan with a paper towel.
Next, add 1 teaspoon oil into the pan along with the green pepper, yellow onion and jalapeño. Cook on medium heat for about 3 to 4 minutes. Remove vegetables from the pan and set aside. Wipe the pan again with a clean paper towel.
Melt 1/2 Tablespoon of butter in the pan on medium heat. Season the shrimp with salt and pepper and add them to the pan and cook for 60 to 90 seconds on each side. Remove from the pan.
Melt another 1/2 Tablespoon of butter in the pan and add 2 tortillas to the pan, half of each touching the bottom of the pan. Put 1 Tablespoon of cheese and half the of the mushrooms on each tortilla, along with half of the onions and peppers. Then add the shrimp and 2 Tablespoons of cheese on each tortilla.
Close the tortilla and continue cooking for about 2 minutes. Flip over and cook for 3 to 4 minutes, until the desired doneness on the inside and outside.