FatSecret Indonesia lists plain nasi uduk at 260 calories for a 160g bowl, which works out to about 163 per 100g. Plain white rice is 130 per 100g. So the coconut milk costs you roughly 25% more per scoop, and a stall scoop is closer to 200g than 160g. That is why the rice alone on this plate is 325 calories before any side dish.
The side dishes are where the plate swings. The default Rp 12,000 to 15,000 breakfast set with egg, tempe orek, bihun and kerupuk is around 600 calories. Swap the egg for a piece of ayam goreng and you add about 390 calories. Add semur jengkol and another 150. The nasi uduk with ayam goreng, telur and everything is easily 1,000 calories and it is 7am.
Tempe orek looks innocent but it is fried tempe tossed in kecap manis and sugar. A small spoon of 40g is about 90 calories, and a lot of that is sugar. Bihun goreng is 60 calories per spoon, again mostly oil. Neither one is the enemy on its own, they just stack.
For 600 calories you get only 18g of protein, which is the actual weak point. The rice and bihun are 80g of carbs. If you want this to hold you until lunch, the fix is more egg or more tempe, not more rice.