Glee Cafe’s one of the newer cha-chaan-tengs in Hong Kong that’s got a very clean, white and modern interior. They specialise in fluffy egg + ham/spam sandwiches, omelettes and macaroni in soup, along with various spaghettis and rice dishes.
If you’re trying to avoid carbs, I recommend getting one of their dinner sets (that comes with a main dish, bowl of rice and soup). Simply tell them you don’t want the rice and you’ve got a pretty decent serving of meat+veggies (or just veggies) with soup.
One of their healthier options was the mushroom, bamboo pith and vegetables stir-fry. It’s a bit heavy on cornstarch but otherwise not bad. The price was around HK$45-60 per set, if I remember correctly.