As a rule of thumb, most food is halal. Only when they contain impure elements such as alcohol and porcine ingredients do they become non-halal. So it’s actually not as difficult as one might believe.
The extent that hotels go to to cater for the Islamic market varies. Some are at least alcohol-free, have no nightclub, and serve only halal food. Some others are totally Shariah-compliant, including being halal-certified by JAKIM.
At the end of the day, no matter what your guests’ food preferences may be, be sure to try your best at leaving a good, long-lasting impression on them with good service and definitely good food.