ðə lˈɑːdʒɪk jˈuːʒuːəli ɡoʊz æz fˈɑːloʊz: ðɪ ˌiːˌɛfˈaɪ fˈɜːst lˈʊks fɚɹə bˈuːtloʊdɚɹ ɪn ˌiːˌɛspˈiː, ænd ɪf ðɛɹ ɪz nˈʌn ɪt wɪl kəntˈɪnjuː tə ðə mˈæk ˌoʊˈɛs fˈaɪl sˈɪstəm.
The logic usually goes as follows: the EFI first looks for a bootloader in ESP, and if there is none it will continue to the macOS file system.