Gado-gado means mix-mix, and the name describes the eating rather than the cooking. Every component gets prepared on its own terms, then the whole plate gets tossed together the moment before you eat it.
Jakarta warungs still grind the sauce to order in a heavy stone cobek, one portion at a time, adjusting the chili count for each customer.
Why the mortar beats the blender
A blender cuts peanuts. A mortar crushes them, and crushing forces the oil out of the nut and into the paste. That released oil is what gives the sauce its body, so a blended version needs added fat to reach the same texture and still tastes flatter.
If you only have a blender, pulse rather than run it, and stop while the peanuts are still slightly coarse.
Blanch, do not boil
The vegetables should keep their colour and some resistance. Cook them separately, because each one has a different timing, and cool them quickly so residual heat does not carry them past done. Warm sauce over cool vegetables is the contrast the dish is built on.
