makes 1 sheet pan full, about 2 ½ cups
Bring water to boil, add a pinch or two of salt, and the lentils. Cook at a slow simmer for about twenty minutes, just until al dente. Taste some as you are getting close to the end time so you don't get them too soft.
Drain the lentils in a colander over the sink, shaking out as much water as possible, then turn out onto a clean kitchen towel to pat dry. (White flour sack towels are the best for this and save you from using too many paper towels, but those work too.)
Preheat oven to 425° F.
On a rimmed sheet pan, mix the cooked (and patted dry) lentils with the olive oil, lemon zest (if using), and a sprinkling of salt. Roast in the oven for 15 minutes at which time they should be sizzling and crispy. Keep a careful eye on them if you go longer, as they will burn (and that is sad).