1 medium onion, peeled and cut into chunks
3 medium potatoes
salt and pepper, to taste
3 to 6 T flour
3 T oil
1. Preheat the oven to 400ºF. Butter or oil an 8- x 8-inch square baking pan.
2. The onion and potatoes can be hand-grated, but it’s far easier to use a food processor: put the onion chunks in the bowl of the processor fitted with the metal blade. Pulse on and off until very finely chopped, almost a puree. Scrape into a large mixing bowl. Just before grating each potato, cut it into chunks. Process the potato pieces with pulses, letting the processor run several seconds at the end, to make the pieces no larger than a match head. Scrape the potatoes into the bowl with the onion, stirring them together each time you add potato. The acid in the onion will prevent the potatoes from browning.
3. Beat in the eggs, salt, pepper, and 3 T of the flour. Depending on the moisture content of the potatoes, you may need to add more flour; it should hold together somewhat, but not be too stiff. Add the 3 T oil, mix, then pour into prepared pan.
5. Bake for about 40 minutes, until set and top is browned.