Not spicy isn't helpful in Birmingham, five years ago, I would have gone "Ummm" to your request.
However, things have changed somewhat over the last few years.
The best place in Birmingham is Simpsons, but it is at the pricy end of the market -
http://www.simpsonsrestaurant.co.uk/
For what I regard as reasonable, City Centre and good food, I like the bistro at the Hotel du Vin
http://www.hotelduvin.com/HotelPage....avigationId=12
Similarly the food at the Brasserie Blanc isn't too bad
http://www.brasserieblanc.com/index.html just next to BrindleyPlace.
If you'd like Italian, lots of my fellow Brummies swear by San Carlo
http://www.sancarlo.co.uk/, personally I prefer my neighbourhood "Italian" and I've never liked the service at San Carlo, but it's well loved by many.
If you want Cantonese, best to poke around the Chinese quarter down by the Arcadian. Chung Ying Gardens is the biggest of them all and I go reasonably regularly, but it isn't by far the best
http://www.chungying.co.uk/
There's a pretty good guide at
http://www.birminghamplus.com/ that shows the choice available in the Second City and if you want any questions answered, I'm happy to try and answer them if I can.