Garlicky Shrimp-Cilantro Tacos

This was pretty good and fairly easy to make.  The hardest part about making it is doing the math on the recipe.  This makes like 16 tacos, so we had to decrease everything by a fourth.  It was good and fresh tasting and had some nice heat from the pepper.  We will probably do this again.

Ingredients

• 1/4 cup vegetable oil 
• 1 pound white onions, peeled and thinly sliced 
• 2 or 3 serrano chiles, stemmed, seeded, and thinly sliced (see Notes)
• 4 tablespoons butter 
• 3 tablespoons finely chopped garlic 
• 2 1/2 pounds shrimp (21 to 25 per lb.), peeled, deveined, and halved lengthwise
• 1 cup coarsely chopped fresh cilantro
• Kosher salt
• 32 corn tortillas, warmed (5 to 6 in.; see Notes)
• 2 limes, cut into wedges 

Preparation

• 1. Heat oil in a large frying pan over high heat. Add onions and chiles and cook, stirring frequently, until onions are lightly browned, about 10 minutes. Pour vegetables into a bowl and set aside.
• 2. Melt butter in same frying pan over medium-high heat, add garlic, and stir until sizzling, about 1 minute. Add half of shrimp to pan. Stir often until shrimp are bright pink and no longer wet-looking in thickest part (cut to test), about 5 minutes; transfer shrimp to bowl with reserved vegetables. Add remaining shrimp to pan and cook as above, then return cooked shrimp and vegetables to pan and stir everything together until hot, 2 to 3 minutes. Add cilantro and salt to taste.
• 3. Serve shrimp in a large bowl with tortillas (use 2 tortillas, stacked, per taco), accompanied by lime wedges to squeeze over top.