This is one of those things that I make in which I never measure any of the ingredients, and it is always a stellar meal regardless.
I dice everything small before starting.
onion, about 1/2 large
carrots, about 2 very large carrots
celery, 4-5 stalks
oilive oil, 2-3 Tbs
red lentils, about 1 heaping cup, picked through and rinsed
kosher salt, about 1 Tbs, or to taste
cumin, ground, about 1 Tbs
garlic, granulated about 2 tsp, or 1 large fresh crushed clove
water, tap-hot, about 3.5 cups
vegetable stock, 1 packet
lemon, a good wedge per serving
Basically, I just cook the onions in the olive oil until almost translucent, then add the diced carrots and cook another minutes. When the carrots are almost cooked (I test-taste one or two) I then add the celery and mix it all up well.
After the celery has cooked only for about a minute, I add the lentils, salt and cumin, and stir more. I then add the water and vegetable stock, bring to a boil, then immediately turn to a gentle simmer. Simmer all this (and enjoy the wonderful small as it fills up your house), for about 1/2 hour, or until the lentils are mushy and are cooked. Be sure to stir frequently, as the mixture tends to separate the the lentils fall to the bottom.
One thing I really like to do (I did this time with a great reception) is add about 5 or 6 very large sliced mushrooms. Keep in mind, though, that you may want to reduce the water a bit, since the mushrooms will make it a little more "watery."
Be sure to serve with a nice wedge of lemon which should be squeezed on just prior to eating - this brightens up the flavor nicely.