Pour a small amount of vegetable oil into a large pot and warm it over medium-high heat until hot. Add the diced onion and sauté for about 2 minutes, stirring occasionally until it softens and turns translucent. Stir in the minced garlic and cook briefly until fragrant, about 30 seconds.

Add the ground beef to the pot, breaking it apart with a wooden spoon. Cook until the meat is browned evenly and no longer pink, releasing its juices and flavor into the base, about 5 minutes.

Toss in the chopped tomato and sliced squash, stirring well to combine. Pour in the water, cover the pot, and let the mixture simmer for around 3 minutes to allow the vegetables to start softening.

Uncover the pot and add the eggplant, okra, fish sauce, and tomato paste. Stir thoroughly until the tomato paste is evenly distributed, coating the beef and vegetables. Cover again and cook for another 7 minutes, letting the sauce thicken and the vegetables absorb all the savory flavors.

Uncover once more and season with salt and pepper according to your taste. Stir gently to mix the seasoning through, then cover and let the dish simmer for an additional 5 minutes.

Once everything is tender and flavorful, remove from heat. Serve hot with steamed white rice or alongside your favorite sides such as boiled corn or potatoes for a wholesome, satisfying meal.