For the sauce:
Whisk the sauce ingredients together in a small saucepan over medium heat and bring to a simmer.
Meanwhile, melt the butter in a large skillet over medium-high heat and cook the shrimp for 2 minutes. Stir shrimp and ladle in enough sauce to coat them. Continue cooking and stirring for 2-3 more minutes and the shrimp are opaque. Remove from heat.
Assemble tacos and drizzle extra sauce over shrimp as desired.
