Step 1: Thinly slice the beef sirloin against the grain. Prepare the vegetables: shred lettuce, julienne cucumber and carrot, and rinse bean sprouts. Crush the peanuts.

Step 2: In a small bowl, whisk together fish sauce, lime juice, sugar, minced garlic, and sliced chili to create the dressing.

Step 3: Cook the rice vermicelli according to package instructions (usually soaking in hot water for 3-5 minutes, then draining).

Step 4: Heat oil in a wok or large skillet over high heat. Add the sliced beef and stir-fry quickly for 2-3 minutes until browned and cooked through. Remove from heat.

Step 5: Assemble the salad: Place cooked vermicelli in a bowl, top with lettuce, cucumber, carrot, and bean sprouts. Add the stir-fried beef. Pour the dressing over the top and sprinkle with crushed peanuts. Toss gently before serving.