If using a food processor, use the grating blade to shred the potatoes and onion. If shredding by hand, grate the potatoes and dice the onion as finely as possible.

Have ready brown paper bags or paper towels for draining the latkes. If you want to keep them warm while you work, preheat the oven to 200°F and have a baking pan covered with foil ready.

In a large mixing bowl, mix the potatoes and onions with the potato starch using a wooden spoon or your hands (hands are faster) until the potatoes have released some moisture and the starch is dissolved, about 2 minutes.

Add the salt and pepper. Add the matzoh meal and mix well. Set aside for about 10 minutes. The mixture should get liquidy but sticky.

Preheat a large skillet (cast iron is great, but non-stick works too) over medium heat, on the higher side. Add about 1/4 inch of vegetable oil to the pan. The oil is hot enough when you drop in a bit of batter and bubbles rapidly form around it. If it immediately smokes, the heat is too high — lower it. If the bubbles are lazy, give it another minute or turn up the heat.

Transfer to paper towels or paper bags to drain. Once drained on both sides, place in the warm oven (or covered baking pan) until ready to serve.