Is it sensible to add steamed vegetables to a vegetable curry to reduce cooking time? The objective is to make an Indian mixed vegetable curry like this one. However, the last time I tried it, I had used more vegetables than what the recipe specifies, and needed to cook it for around 40 to 50 minutes until it got cooked.  

Since pressure cookers are able to cook vegetables faster, I considered doing that, and found a recipe which steams vegetables in a pressure cooker. So it made me wonder if I could follow the mixed vegetables recipe as-is until the step where they add vegetables to the pan, and instead of adding uncooked vegetables, I add the steamed vegetables, then that'd reduce the cooking time drastically. I'd assume it'd take a total of:
10 min to steam the vegetables in the pressure cooker.
10 min to sauté the onions, spices and tomatoes in the pan.
5 or 10 min to cook the vegetables after transferring them from the pressure cooker to the pan.  

Does that sound like a sensible plan or is the steaming of vegetables meant to be an entirely different recipe?
I‘m sure you could do this.

But the gain may be less than you calculate and the results will not be exactly the same:


If you are (pre-)steaming the vegetables, your are keeping their individual flavor whereas by cooking in the curry sauce you get a more evened out flavor as the various ingredients contribute to the overall flavor and absorb the spices. This may or may not be what you prefer, but it’s how your first recipe is designed.
If you are using a pressure cooker, you might reduce the overall cooking time, but you are doubling the washing up: two pots instead of one. And most pressure cookers need hand washing.


Another aspect:


If your vegetables took significantly longer than you expected, it’s likely that you used bigger chunks than the recipe author. So if you want to save cooking time, consider cutting your vegetables smaller. Unless your stove has serious problems, the amount of veggies shouldn’t be too much of a factor.


Bottom line:
It’s up to you which approach you choose to reduce the cooking time, as both can work. I personally would just cut the vegetables a bit smaller.