The only thing I can add is to be sure to tailor your pitch to the needs of the company. Brainstorm what you think a business office needs from a lunch vendor . . . . and even ask some of them. Some key elements to remember are reliability and convenience. If you are including cups, napkins, and forks then your service may be a little more attractive. Offering box lunches is another convenience. Make it so ludicrously simple to order and serve your products that people feel silly NOT calling.
The person ordering risks being ridiculed for poor choices, so find a way to earn that trust. I have almost finished preparing a portfolio that I will put into a 3-ring binder that I will use for presentation. I plan to dress for the appropriate office, make an appointment to meet with the key person, approach them with the idea of providing services . . . and SELL myself. the portfolio will include licenses & certifications, newspaper articles about activities and accomplishments, photos of the facility and staff, as well as menu and other sharp looking branded materials. I’ll have a proposal/price listing in addition to a standard menu. Leave behind a sample lunch/snack for the business staff to enjoy with no strings. Follow up call in a week.
This may be complete overkill for most places I would approach . . . but I can GUARANTEE no one else in my county is doing it, and I will be remembered as “that professional pizza guy in Grantville (where’s Grantville?)”.