There are different kinds of lentils, but I've found substitutions work fairly well, if needed. See this website for a good summary with photos of the different types of lentils and all their varying names. The brown or green lentils are much firmer, while the red lentils usually come split, which means they fall apart when cooked, which makes them excellent for thickening soups. Below are the types I've used before:
|Brown (also called Green) - khaki colored|
|Puy Lentils - blue-green speckled|
|Red - salmon colored|
And just for fun, here is one of my favorite shots I took in Istanbul (click on the photo to enlarge it). I love the gray, drab, ancient buildings with the vibrant, stuffed store fronts below. As far as I can tell, these are not shops strictly for tourists. I snapped this shot on a side road as we were (foolishly) trying to follow a map to make our way from the Grand Bazaar to the Spice Bazaar. Hey, it was our first day, and we didn't realize how crazy, I mean CRAZY, those Istanbul streets are - so winding and unmarked, and really almost impossible to follow on a map. The only things that got us to our destination were huge landmarks, like the sea. Istanbul was fabulous, and I highly recommend visiting. It doesn't seem a common destination for Americans.
1 c. lentils (brown, green, puy) *see note below for red lentils
2 c. water
Pick through lentils, removing any debris or shriveled lentils. Rinse in a fine-mesh colander under running water.
Add lentils and water to a saucepan. Bring the water to a rapid simmer over medium-high heat, then reduce the heat to maintain a very gentle simmer. You should only see a few small bubble and some slight movement in the lentils. Cook, uncovered, for 20-30 minutes. Add water as needed to make sure the lentils are just barely covered.
Test lentils to be sure they are done - tender and no longer crunchy. When finished, you may need to drain off excess water.
* To cook red lentils, follow the same procedure, but cook them for 10-15 minutes only.