Grate your potatoes and onions.
Have a strainer lined with cheesecloth or a towel ready over a large bowl.
Squeeze as much of the liquid as possible out of the potato onion mixture.
Before you toss that liquid, there should be some potato starch accumulated at the bottom of the liquid. Pour off the liquid reserving that potato starch and add that potato starch to your potato pancake batter.
In a separate bowl mix the eggs, baking powder, matzo meal, white and black pepper, salt, and parsley.
Put the strained potato and onion mixture back in the large bowl with the reserved potato starch. Add in the egg mixture and combine well.
Have two or three paper towel lined sheet pans ready and the oven preheated to 200 degrees or so to keep cooked latkes warm. Heat one or two 10- or 12-inch frying pans on the stove top with a ¼ - ½ inch of oil in them. If you are working alone, I’d say use only one. Heat to about medium to medium high – you don’t want the oil to splatter but you want it to “get excited” when you drop in some latke batter. The proper temperature is 350°F - 375°F.
Drop in a small amount and test it out. See if it starts to cook vigorously. And cook it through and taste it for flavor. You can adjust seasoning before cooking all of them.
Flatten the batter right after you place it in the pan so it is an even depth and cooks all the way through. Don’t crowd them when you drop the batter in. Give them room to spread and room to cook.
When they are dark brown on one side (nearly burnt as my friend's mom would say), flip them over.
Remove them from the oil when the underside takes on the same color and place them on the paper-towel lined sheet pans.
If you have a helper, have them salt them immediately. If you salt while hot, it adheres and the latkes taste so good, your guests will tell you they are the best latkes ever!
If you are not serving them right away, they will crisp back up in a hot oven (recommend reheating on a baking sheet at 350°F - 375°F). Really they will. Don’t stress out trying to make enough latkes for a crowd while the crowd is there!