Turn the oven on and set the heat to 425 degrees.
Pour the oil on the baking sheet and, using your clean hands or a paper towel, spread it around.
Put the flour on one of the plates.
Put the bread crumbs and/or cornmeal, thyme, salt, and cayenne (if you like spicy) on the other plate. Mix well.
Crack the eggs into the bowl and beat them with the fork or whisk until pale yellow. Add the mustard and mix well.
One at a time, put the chicken pieces on the plate with the flour and move them around until they are lightly dusted with flour. Shake off any excess.
One at a time, add the chicken pieces to the egg mixture and swish them around until they are well coated.
Remove the chicken pieces, one at a time, from the egg mixture, letting any extra egg mixture drip off, and dip each one in the bread crumb mixture, rolling and pressing down to coat each side.
Shake off any extra coating and put each chicken piece on the baking sheet. Be sure to wash your hands with soap and water after handling raw chicken.
Once the oven temperature has reached 425 degrees, carefully put the baking sheet in the oven and bake for 20 minutes.
Using the pot holders carefully take the baking sheet out of the oven. Turn the chicken pieces over with the spatula or tongs, then put the baking sheet back in the oven. Bake until golden brown, about 20 minutes more.
Serve right away, with a quarter of a lemon on each plate, or set aside to cool. Cover and refrigerate up to overnight.