Чечевица с овощами оказалась вкуснее, чем я ожидал.

Yes — in English, lentils is normally plural, but in Russian чечевица is usually a singular feminine noun when talking about lentils as a food or ingredient in general.

So:

• чечевица = lentils / lentil
• grammatically it is feminine singular
• that is why the verb is оказалась and not a plural form

In this sentence, чечевица с овощами means something like lentils with vegetables or a lentil dish with vegetables.

Because the preposition с meaning with normally takes the instrumental case.

So:

• овощи = vegetables (nominative plural)
• с овощами = with vegetables (instrumental plural)

This is a very common pattern:

• чай с сахаром = tea with sugar
• кофе с молоком = coffee with milk
• рис с овощами = rice with vegetables

So с овощами is exactly what Russian grammar requires here.

Оказалась comes from оказаться, which often means to turn out to be, to prove to be, or to end up being.

So:

• была вкуснее = was tastier
• оказалась вкуснее = turned out to be tastier

The second version adds the idea of surprise or unexpected result. It matches the second half of the sentence, чем я ожидал = than I expected.

So the sentence is not just describing the food — it is saying the result was better than expected.

Because the verb must agree with чечевица, which is:

• feminine
• singular
• in the past tense

Past tense verbs in Russian change for gender and number:

• оказался = masculine
• оказалась = feminine
• оказалось = neuter
• оказались = plural

Since чечевица is feminine singular, оказалась is the correct form.

Вкуснее is the comparative form of вкусный = tasty.

So:

• вкусный = tasty
• вкуснее = tastier

In this sentence, it works like tastier in English:

• Чечевица... оказалась вкуснее... = The lentils... turned out to be tastier...

Russian often uses this short comparative form directly, without a word meaning more.

Russian usually prefers the simple comparative form for this kind of sentence.

So:

• вкуснее = more tasty / tastier
• более вкусная is possible in some contexts, but it is less natural here

After a verb like оказаться, the short comparative вкуснее sounds much more normal:

• оказалась вкуснее = turned out tastier

Using более вкусная here would feel heavier and less idiomatic.

Чем is the normal word used in Russian to mean than in comparisons.

So:

• вкуснее, чем я ожидал = tastier than I expected
• лучше, чем раньше = better than before
• больше, чем нужно = more than necessary

This is one of the most common uses of чем.

Russian often leaves out information that is understood from context.

Here, я ожидал literally means I expected, but the missing idea is something like:

• чем я ожидал = than I expected
• more fully: чем я ожидал, что она будет = than I expected it would be

In English, we also often shorten this:

• It was tastier than I expected

We do not have to say than I expected it to be every time. Russian works similarly here.

Because the past tense verb ожидал agrees with the speaker, я.

In Russian past tense:

• a male speaker says я ожидал
• a female speaker says я ожидала

So this sentence suggests that the speaker is male. If the speaker were female, it would be:

• Чечевица с овощами оказалась вкуснее, чем я ожидала.

Yes. Russian word order is flexible, although different orders can sound more or less natural depending on emphasis.

The neutral order here is:

• Чечевица с овощами оказалась вкуснее, чем я ожидал.

You could also hear things like:

• Чечевица с овощами оказалась вкуснее, чем ожидал я.
  This puts more emphasis on я.
• Вкуснее, чем я ожидал, оказалась чечевица с овощами.
  This is possible, but more marked or stylistic.

For a learner, the original word order is the best standard version to use.

Yes. The core subject is чечевица, and с овощами describes it: lentils with vegetables.

So the structure is:

• чечевица = subject
• с овощами = a prepositional phrase modifying the subject
• оказалась вкуснее = predicate
• чем я ожидал = comparative clause

In other words, the sentence is about a specific dish: the lentils, specifically the lentils with vegetables.

The main stresses are:

• чече́вица
• с овоща́ми
• оказа́лась
• вкусне́е
• чем
• я
• ожида́л

A rough pronunciation guide:

• чечЕвица = che-CHE-vee-tsa
• с овощАми = s a-va-SHA-mi
• оказАлась = a-ka-ZA-las'
• вкуснЕе = vkus-NYE-ye
• ожидАл = a-zhi-DAL

One useful point: вкуснее is pronounced smoothly as three syllables, roughly vkus-NYE-ye.

Yes, вкусней exists, but вкуснее is the more neutral and standard form.

So:

• вкуснее = standard, safe choice
• вкусней = common in speech, sometimes a little more colloquial or expressive

For learners, вкуснее is the best form to remember and use first.

A useful pattern is:

[subject] + оказался / оказалась / оказалось / оказались + comparative + чем...

Examples:

• Фильм оказался лучше, чем я думал.
  The movie turned out better than I thought.
• Экзамен оказался труднее, чем мы ожидали.
  The exam turned out harder than we expected.
• Суп оказался вкуснее, чем обычно.
  The soup turned out tastier than usual.

Your sentence follows this exact pattern:

• Чечевица с овощами = subject
• оказалась = turned out
• вкуснее = tastier
• чем я ожидал = than I expected

It is a very natural and useful Russian sentence structure.