Formal synonym for "sick of [food]"? [closed]

You can say (from Farlex)

We are fed up with chipotle.

which is literally true too. Of course, you can soften the impact by adding something like

It's great food, but we'd love to be more adventurous / try other tastes / etc.

If you want to be polite/tactful because it's the boss, you could just suggest another place or two and let your boss "get the message". If you do want to give the reason, perhaps:

Could we vary our lunch menu next time and order from A or B instead of Chipotle?

If you do want to refer to the the monotony, perhaps:

We've all gotten a bit tired of Chipotle for lunch. Could we try A or B for a change?