Your questions are related, but involve different subsets of law to answer them.
As you know, uncooked products may not be cooked on Shabbos. What constitutes cooking?
From OC 318:4 and commentaries:
Primary container on a fire (empty or with liquid): Potential to cook anything.
Primary container removed from the fire- still hot: Potential to cook just about anything (not ox meat, maybe not salt).
Liquid poured from the primary container- still hot: Potential to cook a layer of food
Secondary container (liquid poured from the primary)-still hot: Generally cannot cook except easily cooked food (nowadays we consider everything easily cooked unless we know otherwise)
Liquid poured from a secondary container- still hot: Generally cannot cook except easily cooked foods. Here we allow most things unless we suspect it is easily cooked (think salmon).
These have to do with the air and container walls cooling down the dish so that it will not retain its heat long enough to cook.
By the time the chulent or the soup goes from the pot to the ladle to the bowl, you should be good to go except for 2 laws which are argued about, and we are strict when the dust clears:
- Davar Gush/Solid Items (MB 318:47, 65): You've probably noticed that solids retain their heat much longer than liquids. We pasken that solids do not get downgraded to secondary or tertiary container status, but retain their primary "container" status as long as they are hot. So if your chulent is dry, you may have this problem. This isn't an issue if your cole slaw is touching a liquid part of the chulent.
- Bishul achar afiya-cooking after baking (OC 318:5): We pasken that something which is dry baked is not considered cooked in regard to liquid cooking. So baked croutons may be a problem if you put them in a primary or secondary container of hot soup. Again, by the time they hit your bowl, you should be dealing with a tertiary container.
Regarding ladles: Ladles are not easily classified as a secondary container since the liquid was not poured into it but was taken by placing the ladle in the primary container above the fire. I recall from the Shabbos Kitchen book that we are strict to call it a primary container while it is in the ladle and pouring from a primary container when it is poured. However, after it is poured into the bowl and should be a secondary container, we are no longer strict and effectively consider it a tertiary container.
Accordingly, you should not pour the soup from the ladle onto the croutons, but may place the croutons into the soup after it is poured from the ladle.