Combine the fish sauce, lime juice and black pepper in a gallon sized sealable bag. Add in the strips of flank steak, seal the bag, and toss to coat all of the beef. Place in the refrigerator for at least four hours, but preferably over night.
Heat up your gas grill, or preferably charcoal grill on high heat. During this time, take the beef out of the refrigerator and let it come up to room temperature. When the grill is heated, lay the beef onto the grill and cook for a couple of minutes per side. The beef will cook quickly. Once cooked, remove from the grill and place into a mixing bowl.
Let the beef rest a few minutes so that it releases it natural juices, allowing for a nice dressing. Add the green onions, mint, shallots, toasted rice, and chili pepper into the bowl of beef, and give a good mix.
To serve, arrange the beef salad onto your serving dish, and place some roasted peanuts, lettuce or cabbage leaves, and fresh cucumber slices. Serve with Thai sticky rice, or regular jasmine rice.
Your result is an awesome grilled beef salad that hits the spot in terms of a bit of sourness and spice. It's super fresh from the mint leaves, and either pinched up with some Thai sticky rice, or folded into a lettuce or cabbage leaf, this one is sure to have you coming back for more. I hope you enjoy!