I was taught never to use curry powder but to blend the spices for each dish so I was surprised to see it in your recipe.

If you find a particular spice/curry mix that you like, use it. My BBF and former college roommate is Punjabi and she said her mother bought her spice mixes from particular brands/shop because there are so many variations, it was difficult to replicate the stuff that they really loved. When her mother switched brands, they could always tell and often didn't like the new stuff. She rarely made her own. She just didn't have the time and the shop-bought stuff was fantastic. So save yourself some stress and find a good curry mix that you like :)

I think you should stick to your guns. You maintain much more control of your dish, and mixed curry powders not only contain things you might not want, they're unlikely to balance as you want, and most often overemphasize the cheaper ingredients. They may be OK for making quick and easy sort-of-Indian dishes, but if you're serious about what you're doing you're far better off making your own (or using the recipe author's) decisions.

Well, since curry powder is a blend of spices, if you find one you like, why not use it?

Cooking isn’t always about being authentic to the letter if the law. It’s about making tasty food.