The siomay are the light part. Steamed fish paste in a thin wonton skin is 51 calories each according to FatSecret, 138 per 100g, with 4.5g protein per piece, which is a good ratio for a street snack. Three siomay is about 155 calories and 13g protein. If the plate stopped there it would be one of the best snacks in Indonesia. It does not stop there.
The rest of the plate is steamed, not fried, so it looks innocent. But the potato is 65, the tahu is 60, the egg is 75, and then the peanut sauce goes on. Siomay sauce is thick, 50g of it is about 170 calories, and the seller ladles it until nothing is visible. Kecap manis and sambal on top add 25 more. So the standard Rp 15,000 to 20,000 plate is 580, and 30g of it is fat, nearly all from the sauce.
The bitter gourd and the cabbage roll are the free part at about 25 calories together, and the pare is the thing people leave. Eat it. Lime is free and cuts the sauce so you need less. The egg is the best value on the plate, 75 calories for 6g protein.
Siomay ayam (chicken, the Bakmi GM type) is a bit lighter per piece at about 30 because it is smaller. Siomay from a mall food court with 5 pieces and sauce is around 400 because there is no tofu or potato.