Pronunciation: [ɹˈɒste͡ɪŋ] (IPA)
Correct spelling for the English word "rostaing" is [ɹˈɒste͡ɪŋ], [ɹˈɒsteɪŋ], [ɹ_ˈɒ_s_t_eɪ_ŋ] (IPA phonetic alphabet).