I cook curry (spicy gravy) for 2, and I cook 4 servings each time. I usually make vegetarian curry. Each curry is different, some have more cinnamon or star anise, or more mustard seeds, or more heat or less.
We use the curry pastes for the galangal, chilies (for heat), lemon grass.
For us two, I put in 1+ tablespoon of curry paste and that is the amount of heat that we like.
Fry that curry paste and then I add coriander crushed, oregano (from the garden), turmeric, curry powder (which is a mix of turmeric, coriander and other spices), chopped garlic, chopped ginger, then optionally some garam masala (which I make, black pepper, anise, cinnamon), optional soaked and ground mustard seeds, then of course you can add whichever spice you want to emphasis for that particular dish.
After frying it to bring out the smell, vegetables for the sauce are added, like onions, tomatoes, or onions, pulp of sweet potato. Whatever you make you want it all for the sauce, so you can blend it with a hand blender.
Then the richness factor, you can add butter, or you can add sour cream, or you can add coconut milk or cream. Then I cook it down until it is a smooth, creamy, and fragrant sauce.
I add a touch of sweet, maybe 1 T sugar or honey, then a tsp. of salt. Tomatoes have a sourish taste but if not that, then add a little lime juice/lemon juice/tamarind to lift it up.
So you find a balance of spices, heat, slight salt, slight sweet, slight sour that you like. As rich as you like. (the missing flavor is bitter but you can add bitter vegetables as well)
Then I add the mixture of vegetables depending on how long I want them cooked, or I cook them separately and then add them at this point. Zucchini, chopped tomatoes, broccoli, asparagus, pea pods, green/red/yellow peppers, eggplant--not all of them, some of them, cooked to crisp cooked and not mushy. If you want to add fish or paneer or tofu, this is when you add that as well.
This morning I made a tomato/onion curry sauce with coconut milk (not garam masala, cinnamon, mustard seeds) until it was smooth and thick. Then I added pre-blanched/cooked, zucchini, broccoli, asparagus, pea pods. Then I divide it into 4 servings, one in a bowl, and three in containers for taking for lunches to work, frozen or refrigerated. I go weeks at a time, having this kind of vegetable curry once a day, a healthy vegetable dish 'with gravy'.
With DH, he won't eat hot or spicy or fragrant, so I make a gravy that is more bland with garlic/onions/tomatoes/thyme/S&P, with beef or pork, meatballs or chunks, then use the same premade vegetables as a base for him. He's happy with it.