that would have been me. keep your oven low, at about 150-200 and then dry the lemon rind (no white) really slow on a parchment lined baking sheet or on a cooling rack lined baking sheet. it shouldn't take more than 2-4 hours (depends on how much oil and how large your pieces are). it will probably start to turn brown, but it will only get a golden brown color. this is ok. then cool and grind. i add salt to mine sometimes to make a lemon salt for dusting.
Here's a recipe from Vongerichten for ORANGE DUST that I have paraphrased. You should be able to adapt it to lemons. (makes 2-3 Tbs)
1/4 cup sugar
½ tsp canola, grapeseed, or other neutral flavored oil
Peel oranges into 8019 broad strips. Use veggie peeler and be sure to scrape away any pith left on them with paring knife.
Preheat oven to 350f.
--Use small saucepan with 1 cup water and sugar; bring to a boil, then reduce to medium til it becomes syrupy (10-15 minutes). Remove peel; drain.
--On a foil lined sheet pan, lightly oiled, scatter cooked peels. They should not touch each other.
--Bake til dry, but not at all brown, for about 15 minutes. If they begin to brown before dry, lower heat.
--Cool at room temperature (preferably in dry place).
--Crumble, then grind in spice mill til powdery.
--Store in tightly sealed jar.
--Peak flavor lasts a couple weeks, but will keep virtually forever, gradually losing intensity.