I recently encountered a few recipes where food is not allowed to 'get colour', or become brownish while baking. 
A few examples of what I mean: 

* Chicken turns a golden-brown colour. 
* Burgers get a very dark crust. 
* Unions turn brown.

How do I avoid my food becoming this colour when cooking, while still cooking them? Is there a way that works in general or if not, a way to find out how to do this for the food I am cooking today?

**Specifically**, in this [recipe for white asparagus panna cotta][1], a brown colour is undesired.

> Bak de asperges een minuutje of 5; ze mogen niet kleuren!  
> Cook the asparagus for less than 5 minutes; ensure they don't change colour!

<!--- "Bakken en braden" = "Cook and bake" ;-) -->
<!--- 5 minuutjes = minder dan 5 minuten --->

  [1]: https://lekkertafelen.nl/recepten/panna-cotta-van-witte-asperges/