Whisk together the flour, cornmeal, salt and black pepper in a broad, shallow bowl. Transfer the mixture to a small low rim cookie sheet and spread evenly. Wipe the bowl and pour the milk and the egg yolk. Whisk until thoroughly combined.
Preheat the oven at 250F and place a heatproof platter lined, or cookie sheet, with double thickness paper towels inside.
Pour the oil into a 10-inch skillet to a depth of about ½ inch and place over high heat. When the oil is hot, beginning to smoke, turn down to medium high
Submerge the chops, one at the time, in the milk egg wash until completely coated, letting any excess drip back into the bowl. Press each chop firmly into the flour mixture. Coat all sides and shake off excess. Slide them gently into the skillet making sure you do not over crown the oil – 2 at the time. Fry one side for about 3 minutes or golden brown. Turn to the other side and cook for another 3 minutes. (turn one more time if you see blood come thru the bone part of the chop).
Transfer with tongs to the cookie sheet and transfer in the oven. Repeat with the other 2 chops.
Preparing the gravy:
Pour out all but 2 tablespoons of the oil from the frying skillet and add the onions to it. Cook until translucent but not browned, about 4 minutes.
Scatter the flour in the pan over the onions and cook, stirring well until the onions are well coated. Cook while stirring for about 4 minutes and the onions are toasty.
Add the milk and broth and whisk until smooth. Bring to a simmer and cook, stirring, until the gravy is thickened, about 4 to 6 minutes.Season to taste with salt and pepper.
Remove the chops from the oven and arrange them on a long platter. Smother them with the gravy and bring to the table.