Because I’ve heard it:
vermi-chelli
and
vermi-selly
and I’m sure I’m somehow making a fool of myself every time I go to the Vietnamese restaurant for a bowl of rice vermicelli.
Just like Monticello.
I don’t pronounce it either of those ways.
Verma-chelli
It’s a complex word, vur-muh-CHELLLLLL-ih. You have do down play the verma, emphasize the chell, rolling the L’s, and clip the not quite hard E sound at the end. Also, point the index finger outward when you start, and rotate it in two dimensional flourish to pointing straight up at the end, arching the eyebrows as you do that.
Monticello refers to an American house based on an Italian word, so it is a bit ambiguous.
Vermicelli is an Italian word, with no more than a brief stopover so no ambiguity. “Porcini” is not ambiguous either. There should be only one way to pronounce “maraschino” and “bruschetta” but most people mangle those so it’s becoming a losing battle.
I have no idea how it would be pronounced in Vietnamese. It seems their French loanword pronunciations might be more accurate than many.
Next time you’re eating it, remember, it means “little worms.”
“Do you mean the worm, or the spaghetti?”
There isn’t even one way to pronounce Italian words in Italy 
In Italian the “ce” and “ci” are always pronounced with a “ch” sound as in “children” – “che” and “chi,” respectively. So “vermicelli” is pronounced ver-mi-chel-li.
(But to confuse things, in Italian “che” is pronounced “ke” and “chi” is pronounced “ki”. “Bruschetta” is pronounced “Bru-sket-ta”.)
There is no other way to pronounce these four letter combinations unless you’re getting into dialects.
And since I’m here, the “sci” and “sce” combinations are pronounced “shi” and “she”, so Steve Buscemi’s last name would be pronounced in Italian “Bu-she-mi” (I don’t know how he himself pronounces it).
Absolutely correct. In most cases it would be the vowels that change, not the consonants. I think Tuscan is considered the default, no?
Buscemi is given both pronunciations in Wikipedia, I hear “sh” a lot, even in the US. But he also said: “I had to go to Sicily to find out I pronounce my name wrong.” Of course, Sicilian Italian is a whole 'nother can of vermi.
My family pronounce it wrong too! We use long e’s
The worm sir.
Every time I order “brusketta” in a restaurant my friends give me a hard time.
Geddy Lee famously mispronounced “red barchetta” in the song of the same name.