Actually the word "rendang" means "slow cooking". The process can be stopped before 2hrs and it still has a fluid broth it's called "gulai". Or between 2-4 hrs when its broth thicker and it's called "kalio".

But when it comes to origin "rendang" version you will have no broth, yet the sauce with darker color.

Trust me, the taste has better sensation, when all the fat from the meat and coconut completely merge with the spices.

I live alone, so when cooking this, I do this in one big batch, portion the rest and freeze for another day.
Small portions result in unpredictable taste; often than not, you end up not tasting beef at all and require to add beef stock into the pot.

I have 2 CHEATS.
1. Pressure cook the beef with few stalks of lemon grass
This cuts down cooking time by 1-1.5 hour. Add that to your reduced coconut milk and spice paste, and simmer for 30mins, or till dry. Yes, constantly scrape the bottom of the pot regularly.

2. Rice cooker with Keep Warm feature.
Cook as per your recipe till timestamp 5:13. Transfer the whole content into a rice cooker and press the button as if cooking rice. When liquid is reduced, it trick the rice cooker to keep warm mode.
I do this before going to work. By the time I come back end of the day, Beef Rendang is ready. The plus point is, I need not be there to scrape the bottom of the pot.