Когда я готовлю макароны дома, я иногда делаю соус со сливками и чесноком.

In Russian, когда can mean both when and whenever, depending on context.

In this sentence, both verbs are in the present tense:

• я готовлю
• я иногда делаю

That makes the whole sentence sound habitual or repeated, not like one specific event. So Когда я готовлю макароны дома... is naturally understood as:

• When/Whenever I cook pasta at home...

If you were talking about one specific occasion, the context would usually make that clear.

They are in the present tense because the sentence describes a habit or something that happens sometimes in general.

Russian often uses the present tense for repeated actions, just like English does in sentences such as:

• When I cook pasta at home, I sometimes make...

So here:

• готовлю = I cook / I am cooking depending on context
• делаю = I make / I am making

In this sentence, they mean I cook and I make in a habitual sense.

They are imperfective because the sentence talks about:

• repeated actions
• general habits
• process/activity, not one completed result

So:

• готовить = imperfective, to cook
• делать = imperfective, to do / make

If you used perfective verbs here, it would sound more like a single completed event, which does not fit well with sometimes and the general-habit meaning.

In Russian, макароны is normally used as a plural noun when talking about pasta/macaroni in general.

So even though English often says pasta as an uncountable singular noun, Russian commonly says:

• готовить макароны
• есть макароны

This is just a vocabulary difference between the two languages.

There is a singular form, макаронина, but that means one piece of macaroni/pasta, not pasta as a dish in general.

Дома is a very common adverb meaning at home.

So:

• я готовлю дома = I cook at home

By contrast, в доме literally means in the house/building, and it usually focuses more on the physical building itself.

For everyday at home, Russian usually prefers дома.

Because Когда я готовлю макароны дома is a subordinate clause introduced by когда.

Russian punctuation normally separates a subordinate clause from the main clause with a comma:

• Когда я готовлю макароны дома, я иногда делаю...

This is very standard in Russian.

They are in the instrumental case because they follow с / со in the meaning with.

So:

• сливки → сливками
• чеснок → чесноком

This is a very common pattern:

• чай с сахаром = tea with sugar
• хлеб с маслом = bread with butter
• соус со сливками и чесноком = sauce with cream and garlic

Russian uses со instead of с when it is easier to pronounce that way.

This often happens before words beginning with certain consonant clusters, including сл-:

• со сливками
• со мной

So here со сливками is chosen for pronunciation reasons. It means the same thing as с grammatically; it is just the smoother form.

Because чеснок is usually treated as a mass noun in Russian, like garlic in English.

So when you mean garlic as an ingredient in general, Russian normally uses the singular:

• с чесноком = with garlic

If you wanted to talk about separate garlic cloves or bulbs, you would use different wording, such as:

• зубчики чеснока = cloves of garlic

Russian often allows the subject pronoun to be omitted, because the verb ending already shows the person:

• Когда готовлю макароны дома, иногда делаю соус...

That said, repeating я is also completely natural. It can make the sentence clearer and more balanced, especially for learners or in neutral written style:

• Когда я готовлю..., я иногда делаю...

So the second я is not strictly necessary, but it is perfectly normal.

Yes. Russian word order is fairly flexible, although different orders can shift the emphasis slightly.

For example:

• Когда я готовлю макароны дома, я иногда делаю соус со сливками и чесноком.
• Я иногда делаю соус со сливками и чесноком, когда готовлю макароны дома.

Both are grammatical. The original version starts with the when-clause, which sets the scene first. That is a very natural choice.

Иногда means sometimes, and placing it before the verb is a very common neutral position:

• я иногда делаю

You could move it, but the emphasis changes a little:

• Я иногда делаю соус... = neutral, natural
• Иногда я делаю соус... = a bit more emphasis on sometimes
• Я делаю иногда соус... = possible, but less neutral

So the placement in the sentence is the most standard one.

Yes, you could.

There is a small nuance:

• соус со сливками и чесноком = sauce with cream and garlic
• сливочный соус с чесноком = creamy/cream sauce with garlic

The original sentence names the ingredients more directly. The alternative sounds a bit more like a set dish description. Both are natural, but the original is very straightforward and clear.