Heat .25-inch of oil in a skillet on medium-high heat until hot. Fry one tortilla at a time until lightly golden brown, then flip to the other side, about 2 to 3 minutes total.
Remove from the oil and drain on paper towels. Sprinkle both sides with a bit of sea salt.
Preheat grill (gas or charcoal) to high heat.
Toss shrimp with olive oil and Mexican seasoning. Thread the shrimp onto skewers without squishing them together, just lightly touching.
Place on the grill and cook for about two minutes, flip and continue to cook until they are cooked through and browned in spots, about 2 more minutes. Remove from grill and cover with foil.
To Assemble
Place a tortilla shell on a plate and spread refried beans on top. Place several (6) cooked shrimp on top of the beans.
Top with diced tomato, white onion and avocado. Sprinkle cheese and chopped cilantro over the shrimp and drizzle with crema (or sour cream). Serve immediately.
Notes
If you notice any holes in your tortilla, tilt over the paper towels and allow the oil to drain out.
This may be obvious but, use metal tongs to fry your tortillas in the hot oil and move them to a paper towel covered plate to drain.
For easy clean-up and to avoid cross-contamination: place two sheets of foil on a baking sheet or platter before adding the shrimp. After you place the shrimp on the grill, remove the first layer of foil and throw it away. Place the cooked shrimp on the remaining foil and bring back inside.
You can also cook the shrimp on the stove using a cast iron skillet or grill pan, about 2 to 3 minutes per side.
You can bake them in the oven on a baking sheet for about 8 minutes.
You can also broil your shrimp in the oven on a foil lined baking sheet for about 8 minutes, or until cooked through.