Ce dont j’ai envie aujourd’hui, c’est d’une purée maison avec une petite salade et une bonne vinaigrette.

Because the expression is avoir envie de quelque chose — literally, to have a desire for something.

So:

• J’ai envie de ça = I feel like that / I want that
• When the thing is replaced by a relative pronoun introduced by de, French uses dont

That is why:

• Ce dont j’ai envie = what I feel like / the thing I want

You would use ce que for a direct object, but here the verb expression needs de, so dont is the correct choice.

A useful comparison:

• Ce que je mange = what I eat
• Ce dont j’ai envie = what I feel like

This is a very common French structure used to introduce or highlight the thing being talked about:

• Ce dont j’ai envie aujourd’hui, c’est...

It works a bit like:

• What I feel like today is...
• As for what I feel like today, it’s...

The c’est helps present the answer clearly and naturally. French often likes this kind of structure when the speaker first names a topic and then explains or identifies it.

So the sentence is built in two parts:

1. Ce dont j’ai envie aujourd’hui = what I feel like today
2. c’est d’une purée maison... = is homemade mash...

Because the idea of avoir envie de is still active in the structure.

The basic sentence is:

• J’ai envie d’une purée maison

So when French reshapes it into:

• Ce dont j’ai envie, c’est...

the de is kept:

• Ce dont j’ai envie, c’est d’une purée maison

This is very common with nouns or pronouns that depend on de.

For example:

• Ce dont j’ai besoin, c’est d’aide.
• Ce dont il parle, c’est de son travail.

So the d’ is not random — it belongs to the original construction.

Dont replaces de + noun/pronoun.

In this sentence, the full idea behind it is something like:

• J’ai envie de quelque chose
• Ce quelque chose becomes ce dont

So:

• de quelque chose → dont

You can think of dont as meaning:

• of which
• that ... of
• or more naturally in English here, what

It is especially common after verbs and expressions built with de, such as:

• avoir besoin de
• parler de
• rêver de
• avoir envie de

Examples:

• Le livre dont je parle = the book I’m talking about
• Ce dont j’ai besoin = what I need

Because adjective placement in French is not the same for all adjectives.

In this sentence:

• purée maison
• petite salade
• bonne vinaigrette

Here is why:

• petit and bon are very common short adjectives that often go before the noun
• maison in this use means homemade / house-made, and it normally comes after the noun

So:

• une petite salade
• une bonne vinaigrette
• une purée maison

This is normal French word order.

Also, adjective position can sometimes affect tone or meaning, but in this sentence everything sounds very natural and idiomatic.

Literally, maison means house, but in food contexts it often means homemade or house-made.

So:

• une purée maison = homemade mash / homemade mashed potatoes

You will see this a lot in French food vocabulary:

• dessert maison = homemade dessert
• soupe maison = homemade soup
• frites maison = homemade fries

So here maison is acting like an adjective, even though the basic word is a noun.

Not exactly.

• vouloir = to want
• avoir envie de = to feel like, to be in the mood for, to fancy

In this sentence, avoir envie de sounds more natural because the speaker is talking about what they feel like eating today.

Compare:

• Je veux une purée = I want mashed potatoes
• J’ai envie d’une purée = I feel like having mashed potatoes

The second one often sounds softer, more personal, and more about current desire or appetite.

Because that is a very natural place for a time expression in French.

The phrase:

• j’ai envie aujourd’hui

means I feel like today or today I’m in the mood for

French adverbs and time expressions can sometimes move around, but this position is smooth and idiomatic in this sentence:

• Ce dont j’ai envie aujourd’hui, c’est...

You could also say something like:

• Aujourd’hui, j’ai envie de...

But in the given sentence, aujourd’hui fits neatly inside the first clause.

Because the speaker is talking about specific items they feel like having, not things in general.

So:

• d’une purée maison = some homemade mash / a homemade mash
• une petite salade = a small salad
• une bonne vinaigrette = a good vinaigrette

French often uses the indefinite article in this kind of food context when naming a dish or serving.

Also, une petite salade and une bonne vinaigrette add a nice, concrete, appetizing feel. The speaker is imagining an actual meal, not just talking about food in the abstract.

Normally, no. The final t in dont is not pronounced.

It is pronounced roughly like:

• don with a nasal vowel

So it sounds approximately like dohn with a nasal French sound, not like English don't.

A few quick pronunciation points from the sentence:

• j’ai = the e disappears before the vowel
• c’est = ce est becomes c’est
• d’une = de une becomes d’une

These apostrophes show elision, which is very common in French before a vowel or silent h.

Yes, absolutely.

A simpler version would be:

• J’ai envie d’une purée maison avec une petite salade et une bonne vinaigrette.

That means basically the same thing.

The full version:

• Ce dont j’ai envie aujourd’hui, c’est...

sounds a bit more shaped and expressive. It puts emphasis on what I’m in the mood for today before giving the answer.

So the longer version is not grammatically necessary, but it is very natural when the speaker wants a slightly more thoughtful or emphatic style.