Your original sentence is unclear to this extent: Do you mean that each spice should be put in separately (one spice at a time) or that they should all be mixed together into something like a curry powder and then added in equal fractional parts?
I'll assume the former (it's more rational for cooking for a couple of reasons).
You can say it this way:
Rather than adding all (of) the spices at the same time while cooking something, put them in one at a time at regular intervals, for example, every 2 minutes.
You can also say:
... put them in (separately) step by step, ..."
There's no need to clutter the sentence with unnecessary terms like "rounds" and "steps".
This website lists about two dozen three-word phrasal verbs. As I looked through the list, they all seemed "inseparable" to me.
However, have said that, I think there is some wiggle room for a few of these, due to the flexibility of prepositions.
For example, consider talk back to. That form may be the preferred version, but one might see talk back at used instead:
When you're in school, don't talk back at your teacher.
Also, there are times when one of the three words can be cut out altogether, resulting in the use a two-word phrasal verb instead. For example, the website lists check up on as a phrasal verb meaning "examine" or "investigate," with the example:
The boys promised to check up on the condition of the summer house from time to time.
I think one could remove the up and retain the same general meaning:
The boys promised to check on the condition of the summer house from time to time.
As for your example, the preposition could probably changed from on to with, and the result would be a more common way of writing it:
Unfortunately, I wasn't able to keep up with the news while I was away on vacation.
Best Answer
Ciao, Federico
You have used through (definition 5, by means of) correctly in your sentence. Good job.
I will say that it is not all that natural. In other words, it's grammatical and understandable, but not idiomatic, not the most natural way to express the thought.
Through is often used as a result of a middleman, or to signify a process. Neither of these apply to your tips.
Also, are you thanking Alex directly? If so, you need commas before and after Alex:
In addition, tips is ambiguous without further context, as the word can mean either (monetary) tips gained from working as a waiter, for example, or tips as in suggestions. I assume you mean the latter, and in any case it does not much affect the choice of preposition.
Changing no word except through, the following are perhaps preferable:
and
But, frankly, two more natural sentences are
and
Just as many native speakers would not normally choose the preposition through in either of these two sentences, we wouldn't normally choose it in your original sentence. There is no explanation as to Why, rather it's simply a matter of being familiar with which preposition sounds better, or "works" more naturally in a particular sentence.
I am a native speaker of American English.