I grew up in England and the British Indian curry is something that holds a special place in my heart. Surprisingly I have only recently learned that the curry houses use a base gravy to cook their food and now I've been making it in bulk for our own restaurant style curries. Once you've made it it will be enough for 2-3 meals for a family and it freezes well also so is a good thing to keep on hand. The base gravy is basically a spicy tomato soup.
Here's the recipe:
Sauce:
0.5 cup vegetable oil
1 onion
1 1/2 tbs ginger
3 tbs garlic
3 tbs tomato puree
1 kg tinned tomatoes (yeah fresh is better but tinned is fine)
6 green chillis
Spice blend:
1 tsp cumin powder (you can find this in Indian stores)
1 tsp coriander powder (you can find this in Indian stores)
2 tsp turmeric powder (you can find this in Indian stores)
2 tsp curry powder (any kind)
2 tsp kashmiri chilli powder (or medium spice powder of your choice)
1 tsp garam massala (you can find this in Kroger or Indian stores)
Seriously, if you have never cooked Indian food before, fid a local Indian shop and buy some ground cumin, coriander, turmeric and garam masala - these are essentials in almost all Indian dishes.
Put the oil in a pot, add onions and fry for a minute, then add garlic and ginger and fry for 30 seconds, then add everything else, stir together, cover and cook on low heat for an hour. Once it's done, use a tick blender to puree it smooth. If you want a velvety curry, pass it through a fine mesh sieve. Once done you can add:
2 tsp kasoori methi (optional)
2 tsp salt
And jar it up. This is what's in my fridge right now:
My kids favourite is butter chicken:
2 cups base gravy
1 tbs honey
1/4 stick of butter (40g or more)
2 tsp chilli powder
salt to taste
cooked chicken (get a roast chicken from Kroger and strip the meat off the bones)
Bung together and cook for 20-30 minutes and you'll have a curry to die for...
So thick it sticks to everything and the Noods loved it! 
