if you say g-are-ande with an English sounding 'r' you have the worst gringo accent and are actually saying the word wrong.

but it's also inappropriate to roll your r as if the single 'r' was the Spanish letter "rr" like you would with "perro" or "ferro".

in Spanish, a single 'r' should be flipped like Cougarrr says so that it sounds more like a soft English 'd' than an 'r' .

you could transliterate it as 'g-d-ande'