There isn't a standard substitution for curry powder; all the blends are subtly different, and may or may not include any of a dozen or so spices.
The standard grocery store curry powders all have turmeric, coriander, and cumin in large amounts, and a smaller amount of cayenne or red pepper. Beyond that, they may include varying amounts of cardamom, mustard seed, fenugreek, asafoetida, caraway, cinnamon, nutmeg, garlic powder, ginger, black pepper, or clove. How almost all of them manage to taste like pallid imitations of real Indian curry blends is anyone's guess.
I know recipes are frowned on here, but in this case I think it may elucidate things. Alton Brown provides a recipe which will probably get you a good ballpark result:
- 2 tablespoons whole cumin seeds, toasted
- 2 tablespoons whole cardamom seeds, toasted
- 2 tablespoons whole coriander seeds, toasted
- 1/4 cup ground turmeric
- 1 tablespoon dry mustard
- 1 teaspoon cayenne
Either store together and grind before use (whole seeds store longer), or grind it up into a powder and store that way.
From that base recipe you'll have to tinker with all of the additional spices to get your own substitution.
Best Answer
I like to add unground spices (cumin seeds, mustard seeds, fennel, star anise etc. and of course garlic and chili depending what curry I am making) at the beginning, gives a better flavour to the oil. Then I would add meat and/or veggies, stir fry them a little bit, and finally add the ground spices and water. Water will dissolve the spices and will make it easies to have them cover the veggies uniformly. This is very important especially for turmeric which, if added in oil, only results in a mess. I find ground cumin or coriander are less problematic.
If the ground spices sticked to the veggies you should have just added some water, not oil, which has probably made things worst.
Also, as I generally use fairly high temperatures with the spices at the beginning, I would use vegetable oil (I use sunflower oil) or ghee (clarified butter) rather than olive oil.
PS: no need to be depressed for a meal that did not come out OK. That is how you learn cooking!