In a bowl, combine the lemongrass paste, fish sauce, oyster sauce, sugar, ginger, 1 chile (some or all seeds removed, depending on your heat tolerance), and garlic.
Add meat and toss to coat. Cover and refrigerate for up to 24 hours.
In a jar or bowl, combine the dressing ingredients (warm water, fish sauce, lime juice, sugar, garlic, and chili). Shake or whisk to combine. Chill until ready to use.
Cook the rice vermicelli noodles according to the package instructions. Drain, then transfer the noodles to a large salad bowl. Add the shredded carrots, cucumber, bean sprouts, cilantro, and mint. Pour half the dressing over the noodle mixture and toss gently to coat.
Remove the meat from the refrigerator.
Heat a large skillet over medium-high heat. Add the peanut oil. When hot, add the beef and spread it out in the pan so as much of the meat is touching the surface as possible. Don’t touch it until the top of the meat is no longer pink. Flip the pieces over and continue cooking. You’re looking for a light char on each of the pieces. When done, remove from the pan.
Add your vermicelli salad to the plate. Top with stir-fried beef and drizzle on more dressing, as desired. Serve with crushed peanuts on top.