I usually use the brown/green lentils. I do have some red lentils in the pantry, but have not tried them in this recipe.... yet. LOL
Side note on the recipe - after the first baking session, when I stir to mix up the seasonings, it looks like there is a lot of liquid left, but that is usually gone after the second "uncovered" baking. And I definitely like using my casserole dish over the 9 x 13 pan. Casserole dish makes a "deeper/thicker" dish versus it being spread out in the 9 x 13. Just my preference. LOL.