Why does my Indian curry never taste like it did in English curry houses?

Try warming your spices before adding other ingredients. It helps mature the spices flavour. I usually warm all seeds to "popping" before adding other ingredients - eg. mustad seed, cumin seed.

I note that you didn't list cumin or fenugreek or in your spices. Both have very distict flavour that you might be missing, and they don't always appear as part of every recipe.

Also, using a bit of ghee, coconut milk, or yogurt towards the end of cooking can help the mouth feel and may help combine the flavours a bit more.

There are so many ignorant people out there that take an instant dislike to curry even though they haven't tried it themselves if they did they will soon relies what there missing.. I come from a tiny village in the uk where Indian food is non-existence but once I moved to the big city (12 years ago) where there are loads of Indian restaurants I can honestly say wow I love Indian food but not the hot curries... Lol... My insides can't tolerate it... Also I have a lot of Indians working with me and when they do there food at home they always bring some in for me and boy it's fantastic.... So in my eyes ignore what they say or ask them if they have tried it if no is the answer tell them to try it and then get back to you but I can tell you now they won't cos it great... Hope this helps...

Each Indian Restaurant in London tries to be different than the other guy so they blend their own spices. To get an exact match from any restaurant is almost impossible.

Anyway, there is a key (secret) ingredient used in curries and that is green apples (either sliced and cooked to a pulp then added to the curry or made into an apple sauce and added to it)

Peace

You may be missing the more subtle flavors that come from spices commonly included in Gharam Masala. Things like clove, black pepper, cardamom, star anise, cinnamon.

Different curries take different spices, but cumin and coriander (crushed seeds, not just the leaf) are found in many of them.

Most of the curry dishes I make involve frying onion, garlic-ginger-chili paste, and some spices that are oil soluble for their flavor (cumin, the spices that aren't in gharam masala). The spices depend on the dish. Then I add the other ingredients, meat vegetables, liquid, etc. Gharam masala should be warmed more gently, so I add it after the liquid.

Coriander powder seems missing. It coriander powder had a different taste compared to the fresh coriander (clilantro) leaves

Many curry houses make their own recipe daily to their own recipe and you would have to experiment yourself to recreate it at home.

You're missing haldi! Have you added turmeric powder?