For the Nam Jim Jaew: In a mortar and pestle, pound chile and garlic until a paste is achieved. Add remaining ingredients and mix to combine. Set aside.
For the Green Herb Oil: Bring a small pot of water to a boil. Blanch herbs 15 seconds, then immediately shock in ice water. Once cooled, squeeze out excess water. Transfer herbs to a Vitamix blender and slowly stream in oil until mixture is emulsified. Strain through a cheesecloth and store in an airtight container.
To Assemble and Serve: Brush beef with oil. Between two pieces of plastic wrap, pound beef with a meat mallet until paper thin. Transfer to the center of a serving plate. Squeeze lime juice over meat. Drizzle 1 teaspoon Herb Oil and 1 tablespoon Nam Jim Jaew Sauce over top. Garnish with red onion, Thai basil, Thai chile, and toasted rice powder.
