When I cook lentils I make them into lentil and rice stew.
Mince a large onion or a few bundles of green onions, and several jalapeno peppers, a red bell pepper, and an entire bulb of garlic. Saute them in butter, coconut oil, bacon grease, or whatever is available to you. I sometimes add half a pound or a pound of sliced deli ham, minced, or about a pound of lean ground beef, chicken, et cetera, but this is optional. Saute it all until the onions begin to caramelize. You can get the meat to begin to brown a bit too, but cooking all the meat all the way through isn't necessary at this stage.
Deglaze the pan and get everything into a large kettle with a gallon of water. Bring the water and onion mixture to a boil. At this point additional seasonings would be good. A tablespoon each of salt and pepper, and a bay leaf, are a good start, but this is very personal. Just keep in mind that it's a big batch and a lot of stuff to season. If you like bouillon cubes then we're talking about anywhere from ten to twenty, for example, for this much liquid, depending on your preferences. Get it all boiling. While you're waiting for it to boil, pour in a can of mixed vegetables, to give it a bit more color and texture. When it's all boiling, add one pound of washed lentils and one pound of brown rice.
Bring it all back to a boil. Keep stirring it. The lentils in particular are prone to going to the bottom in a dense sticky mass that won't cook properly if you don't keep them moving.
When it is all back at a rolling boil and the lentils are circulating and not in a glob at the bottom of the pan, I like to add one of those small cans of tomato paste. Break it up and mix it in with a wire whisk, don't just plop it in there. Get it mixed more or less uniform.
Now put a cover on that kettle and put it in the oven at about 275 F. Or 135 Celsius, if you prefer. Let it all simmer for a few hours. It will lose a fair amount of water and the liquid level will drop, but that's okay. Stir it before serving with oyster crackers. The leftovers freeze beautifully.
I know this isn't /fit/ but lentils + rice gives you all the needed amino acids for animal metabolism. It'll also be fairly high in fiber, vitamins, and iron.