Green Mango Salad with Grilled Beef

Name: Green Mango Salad with Grilled Beef
Ingredients: 1-2 bird's-eye chiles, stemmed and chopped; 1 clove garlic, peeled and chopped; 4 1⁄2 tsp. sugar; 4 1⁄2 tsp. Vietnamese fish sauce; Juice and some pulp from 1/2 lime; 3 small shallots, peeled; 1⁄2 cups vegetable oil; 2 stalks lemongrass, trimmed, tender inner parts only, minced; 2 tsp. Vietnamese fish sauce; 1 tsp. soy sauce; 1 tsp. sugar; 1⁄2 lb. beef top loin steak, sliced against the grain into 1⁄4-thick strips; 1 green (unripe) mango, peeled, pitted, and thinly sliced; 6–8 sprigs cilantro, chopped; 1⁄4 cups Asian basil leaves, torn into thirds; 2 Tbsp. unsalted roasted peanuts