This is simple, not very hard at all.
First of all, DO NOT just introduce yourself to her! It'll freak her out, coming out of the blue and she'll only be polite to you due to your being a customer. Besides. Toronto chicks ( I can only assume you're in T.dot) are the coldest, hardest chicks to approach from all the cities I've ever lived in.
What you have to do is get yourself INTRODUCED to her. Strike up a conversation with any of the guys that work there, usually sports related - always a safe route. Once you got a connection, ask about her, if she's married, taken, whatever. That's when you'll know you if you can make a move.
Once you have her attention, you'll have to find a suitable moment to actually talk to her, probably her break or end of her shift. In the middle of her busy day will be no use to you at all. Once you have conversation time with her, talk about music or movies. Always a safe topic. Stay away from religion or politics. This way you'll gage her tastes and find out more about her. Leave it at that until the next time you go in for pizza. Then bring her a little CD or DVD of something she mentioned she liked. Do not give it to her directly! Leave it for her with a little note including your phone number.
She'll call you to thank you and then you have her attention and you can ask her out. If she doesn't call, then she has No Class, even to make a phone call and you'll know she's not worth the chase.
Even of she doesn't call, it leaves the door open to talk to her next time you go in. She might be a little shy to call but would like to speak with you. Again, if she doesn't even say "thanks" she's not worth the effort.
Be cool and confident. If she picks up you're nervous, you'll blow it. If you come off calm and confident (never smug), you'll have her panties on your bedpost.
Off you go! Report back and remember, all women love being payed attention to.
