You will need:
A non-cast-iron frying pan, some grease, part of an onion, some yellow curry powder, some kind of stock or broth or beer would probably work too, potatoes, red lentils, a tomato-based product, a green leafy thing, salt, and lime.
Take the pan. Heat the grease in it. In the hot grease, pre-cook your curry powder. You may also toast mustard seeds, if you have them. They will help make it nice.
Into the hot curry-contaminated grease, place at least half a chopped onion and, if you have some, some chopped garlic. Sautee until the onion is soft and clear. Add your potato, diced however large seems good to you. Small white potatoes with skin on or red potatoes or something waxy are better than baking potatoes, but baking potatoes will work.
Add your tomato-based product. I usually use a tin of tomatoes, but leftover spaghetti sauce will work okay. Tonight, I used some leftover Newman's vodka sauce. I bet you could use old salsa too. Tomato paste might be too much. Tomato juice or V8 should work.
Fill most of the frypan with stock, or beer, or stock and water, or whatever. If you are a vegetarian, do not use an animal based product. Add one or two or three handfulls of red lentils on top. Turn the whole mess down to simmer.
Come back every half an hour and see if the lentils are cooked, or if you need to add fluid.
When the lentils are cooked, take the cover off and let the mess cook down a bit, if it needs it. When it is the right consistency, turn the heat off, throw your handfulls of frozen kale or mustard greens or spinach or whatever on top. Cover. Walk away for five ten minutes.
Come back, stir it all together, and serve with a little salt and lime juice.