Blend the cilantro stems, chili, garlic, salt and lemongrass in a food processor until smooth.
Season the beef with 1 tsp. of salt and ½ tsp. black pepper. Let the beef sit at room temperature for 30-60 minutes for the best results.
Heat the grill to a searing hot temperature (500+ degrees) and cook the beef for 20 minutes a side (internal temperature of 125 degrees for rare).
Remove from heat and let rest for about 10 minutes.
Combine the greens, onion, tomato, cilantro and mint in a large bowl.
After it has rested, slice the beef against the grain and lay on top.
Drizzle with the dressing and garnish with the fried shallots and crushed peanuts.
I recommend cooking the beef rare (125 degrees) for the best results. For medium rare, cook it to 135 degrees, and for medium 145 degrees. But really, try it rare guys.
To let the flavors meld, you can make the dressing the day before. The dressing is even better on the second/third day.
Don't put the dressing on until you're ready to eat. The dressing can make the greens soggy if left on too long.
A good quality beef will work the best for this recipe. I use Choice sirloin, but tenderloin or strip would also be good. I don't recommend tougher cuts as we are not marinating the beef to tenderize it.
Slicing the beef against the grain helps to keep it tender.
For a spicier salad, slice Thai chilies (as many as desired) and put them directly in the salad. You can also add additional chilies to the dressing.
Lemongrass paste is used for convenience, but fresh lemongrass can be substituted if you have it.