A basic food eaten with every meal in a particular cuisine or diet is a staple of that cuisine or diet. This term is most common, I believe, when referring to the main source of carbohydrates like bread, rice, potatoes; it would be unusual to use it in reference to a vegetable, but perhaps that is what you are trying to say.

Broccoli isn't exactly a staple of the American diet.

Definition of caramelize

That word is caramelize, to cook something until its sugars turn to caramel at around 410° F. Recipes will often call for sautéing onions until they caramelize, for example.

The Wikipedia article on caramelization from which the image above was taken says that it is:

the browning of sugar, a process used extensively in cooking for the resulting nutty flavor and brown color. As the process occurs, volatile chemicals are released, producing the characteristic caramel flavor. Like the Maillard reaction, caramelization is a type of non-enzymatic browning. However, unlike the Maillard reaction, caramelization is pyrolysis, as opposed to reaction with amino acids.

Origins

The OED says that English took the word caramel from French and that they in turn adapted it from the Spanish, Portuguese, and Italian word caramelo. Larousse says that the French took it from the Spanish and that the Spanish took it from the Portuguese, and the DRAE confirms that the Spanish got it from the Portuguese. But somewhere in Iberia the trail grows cold, and the OED ultimately says that it is of uncertain origin, providing this note:

Scheler suggests that the Spanish represents Latin calamellus little tube, in reference to its tubular form; Mahn thinks it from medieval Latin cannamella sugar-cane: an Arabic source is conjectured by Littré.

Variable Pronunciation

Actual pronunciation of the word caramelization varies between /ˈkɑɹməˌlaɪz/ with three syllables (“karma lies”) and /ˈkeɹəməˌlaɪz/ with four syllables (“carry m’ lies”).¹ The shorter three-syllable version is probably the more common of the two in North America except on the East Coast and in the South, although either could be heard pretty much anywhere across the continent.

This is because there are two different underlying pronunciations for caramel possible: one has three syllables, /ˈkeɹəˌmɛl/, and the other has only two syllables, /ˈkɑɹməl/. Wiktionary claims of caramel that:

Both the two syllable and the three syllable pronunciations are very common in all regions of the United States, but the trisyllabic pronunciation is more common than the disyllabic one in the South (excluding western Texas), northern New Jersey, eastern New York, and New England, while the disyllabic one is more common than the trisyllabic one in other regions.

Neither pronunciation should be confused for Carmel as in Carmel-by-the-Sea which is contrastively stressed on the second syllable, so /kɑɹˈmɛl/. This does, however, suggest a path towards forcing a particular pronunciation if one is so inclined.

Forcing a Particular Pronunciation

You normally can’t tell from reading something how the writer expected it to be pronounced, but in some forms of verse you can. Here’s a bit of doggerel to force the reader into one or the other of the two pronunciations.

With a “Missing” Syllable

Using a bouncy limerick:

There was a young lady from Wheaton
Who swore that the best thing she’d eaten
           From Carmelite nuns
           Was caramelized buns
With pockets to hide all the meat in.

That one demands the “carmelized” pronunciation that’s missing a syllable to match Carmelite and to have the right stresses and syllable count to fit the meter. There is no sound at all between the r and the m in both those words. People who say “carmel” with two syllables (usually) also say “carmelized” with three.

With an “Extra” Syllable

Using the flickering trisyllabic assonances of Tolkien’s Errantry:

Columbus sailed his caravels
       In parallels across the seas
In search of spicy caramels
       And fairy shells and colonies.

That one demands the “caramels” pronunciation with the extra syllable to match caravels, parallels, fairy shells — and to have the right stresses and syllable count to fit this more exotic (and much more difficult!) verse form. There is a schwa sound between the r and the m. People who say “caramel” with three syllables say “caramelized” with four.

Footnotes

1. Don’t worry too much about the broad phonemic transcriptions; these represent phonemes only, not exact sounds. Some speakers may even realize that phonetically as [ˈkæə̯ɹəmɪ̈ˌlaɪz].