Preheat oven to 450 degrees.
Create the salad. Combine lettuce, red onion and cilantro. Drizzle with lime juice and olive oil. Toss to coat. Cover and refrigerate until ready to serve.
In a saucepan over medium low heat, heat salsa. Stir in shrimp and cook for 2 minutes. Set to the side.
Cover two large baking sheets with foil. Evenly divide the corn tortillas between the two pans. Brush vegetable oil on top of each tortilla. Flip to the other side and brush that with vegetable oil as well.
Evenly divide cheese amongst the 12 tortillas. Top with shrimp salsa mixture.
Bake for 8-10 minutes rotating the baking sheets halfway through the cooking process. They are done when the cheese is melted, and the edges of the tortillas are crisp. While the Taco-dillas are cooking, cut your avocado and add to the salad.
In a roasting pan/dish, fold taco-dillas and stack them next to each other in the pan. This will keep them all upright and easy to serve. Top with salad and a dallop of sour cream or serve salad on the side.