Step 1

Heat a 12-inch skillet or wok over medium-high heat for 1 minute, then add the oil and let heat for another 30 seconds — it should be hot but not smoking. Stir in pork and 3/4 teaspoon salt, and cook, breaking up meat with a spoon, until browned and crisp, 6 to 9 minutes. Transfer to a plate.

Step 2

Return pan to heat and add more oil if it looks dry. Stir in green beans, cook until they are crisp, tender and bright green, 1 to 3 minutes. Stir in chiles, ginger, garlic, coriander seeds and remaining 1/4 teaspoon salt. Cook, stirring frequently, until fragrant, about 1 minute longer.

Step 3

Return pork to skillet, along with chopped cilantro, vinegar, soy sauce and sugar. Stir briefly to combine, then scrape into a serving platter.

Step 4

Sprinkle more vinegar and soy sauce on top to taste, then top with more chopped cilantro. Serve with rice, and sliced tomato, if you like.