Gently smack cucumbers with a rolling pin or the bottom of a heavy pot until they begin to break apart. Tear into bite-size pieces.
Heat oil in a large cast iron over high heat. Add beef and break apart using a wooden spoon and season with salt and pepper. Cook, undisturbed, until bottom side is browned and crisp, about 5 minutes. Break up meat with a spatula and stir to cook the other side, about 5–7 minutes more.
Add the garlic, red pepper flakes, sambal and Fresno chiles to the beef and cook until fragrant, about 2 minutes. Add shallot and smashed cucumbers and cook, tossing occasionally and scraping up any browned bits, until cucumbers are softened and translucent, about 4 minutes. Remove skillet from heat and stir in vinegars, water, soy sauce, and sugar. Reduce heat to medium and cook, stirring, until sauce is reduced slightly, about 3-4 minutes. Season with salt and pepper to taste.
Spoon beef and cucumbers over bowls of coconut rice and top with herbs and lime wedges.

Thai Beef Larb with Coconut Rice

Ingredients