For the gastrique: In a small saucepan, combine sugar, vinegar, red pepper flakes and jalapeno. Bring to a boil and simmer until reduced and thickened to a sauce consistency. Set aside.
For the salad: In a large bowl, combine spinach, red bell pepper and mango. Toss with vinegar and oil and season with salt and pepper.
In a large skillet over medium-high heat, melt 2 tablespoons butter. Add shrimp and cook until they just begin to turn pink, about 1 minute. Remove pan from heat, add tequila and return pan to heat. Carefully ignite tequila and let the flames die down.
Add 1/2 cup of the gastrique and cook, stirring, until shrimp are glazed with the sauce and cooked through, about 1 to 2 minutes. Remove pan from heat, whisk in remaining 2 tablespoons butter in pieces until sauce is thick and smooth.
Serve shrimp on salad, drizzle with sauce.
Recipe courtesy of Brook Harlan