
In a large skillet (an iron skillet preferably), add some butter and saute the onions and bell peppers. Cook until soft for about 2 minutes.
Add the shrimp and cook for another 3 to 4 minutes or until the shrimp is no longer translucent. Note: Make sure not to overcook the shrimp as it can become rubbery.
Season with salt and pepper to taste.
Assemble the tacos by adding a layer of shrimp and top it with shredded cheese.
On a separate skillet, melt some butter with 1 tablespoon of olive oil. Place the tacos open to warm up the entire tortilla. See note
As soon as the tortilla becomes soft, using a spatula, fold it to cover the shrimp side.
Flip the tacos to brown the other side. Cook until crispy and the cheese has melted. Repeat process until all tacos are done.