Toast and Grind the Rice: In a dry pan over medium heat, toast the uncooked sticky rice until it’s golden brown. Remove from heat and use a spice grinder, blender, or mortar and pestle to grind the rice into a powder. You don’t have to turn it into talcum powder, but break it up well.
Prep the Sugar and Tamarind: Carefully shave down the palm sugar with a large chef's knife. Dissolve your tamarind concentrate in hot water and strain out the seeds so it's the consistency of applesauce.
Slice the Aromatics: Slice your shallots and green onions nice and thin. Roughly chop your fresh cilantro (or culantro) and optional mint.
Whisk the Base: Combine fish sauce, lime juice, tamarind paste, and palm sugar in a bowl. Whisk until the palm sugar is fully dissolved.
Incorporate Rice & Veggies: Add in the ground rice powder, sliced green onion, and shallot. Stir to incorporate.
Add Herbs: Add in your fresh herbs.
Bring the Heat: Add your ground dried Thai chiles (or red pepper flakes) ½ tablespoon at a time, tasting as you go until you reach your desired heat level.
Grill your steak: Grill your steaks to the desired doneness. Rest for 5-10 minutes. Slice and serve with your Nam Jim Jaew sauce.