First prepare the loofah / luffa. Wash and dry. Then slice at an angle into ½-inch wide pieces.
In a large pan over medium-high heat, add a little oil followed by the minced garlic. Cook the garlic until it just starts to turn golden.
Then add the sliced loofah. Stir fry for 2-3 minutes until it softens.
Season with the fish sauce / nuoc nam.
Then gradually add ½ cup water to the pan. Add less water if you want it less saucy.
Keep cooking for another couple of minutes until the loofah is soft and tender and about half of the liquid has evaporated.
Taste, and if you want it more flavorful, season with a little more fish sauce (or add a pinch of chicken bouillon).
Give everything one last stir to combine. Then it's ready! Enjoy hot. Best with rice.