Here's what I remember of the original recipe my mom improvised when I was 10ish. It inspired the one Chris posted on this week's blog (It's the other way "that's been delicious").
From the bottom up, in a rectangular (or not) baking dish).
French Lentils (cooked, or soaked overnight or for at least 6-8 hours). I recommend cooking, but don't overcook them (you want them to have texture in the finished dish).
Thinly sliced potatoes.
Whole raw Chard leaves with ribs removed (you can sauté the ribs up with onions and garlic and add to the lentils). Layered at least 3 leaves thick.
Cheese. Suit to your flavor preferences. Mild and creamy for kids, or strong and pungent if you’re into that). It’s nice for the top of the “lasagna” if the cheese is a melt and brown variety.
Experiment heavily: I remember this recipe from a long time ago, and that it was delicious, but I don’t know all the tricks. ie: what temperature was it baked at in order to get the potatoes and lentils to cook, how many reiterations of these layers did it have? My sense is that as long as there is sufficient moisture in the pan (try using broth for added flavor) you could start with soaked lentils, and raw potatoes and end up with perfection. You’d probably want to bake it covered and at a low temp. 300 for a while, 40 minutes plus? Also try experimenting with seasoning styles; I bet Indian spices, or Black beans and Salsa would make nice variations.