Potato Bake with Bacon and Onion

Preheat a conventional oven (no fan) to 180°C and position the rack in the middle. Grease the bottom and sides of a metal baking pan with internal dimensions of about 28 × 20 cm and a height of about 6 cm using the first 10 ml oil. Have ready a 28 cm skillet, a grater with very fine, pointed teeth, a fine-mesh sieve set over a bowl, and a separate large mixing bowl with a capacity of about 4 l. The fine grating surface should turn the potatoes into a pulp, not long shreds.

Cut the 250 g bacon into cubes about 5–8 mm across and place in a cold skillet without adding oil. Cook over medium heat for 10–12 minutes, stirring frequently, until the fat renders and the bacon pieces are lightly browned. Do not let the residue turn black; reduce the heat if needed. Leave all the bacon and rendered fat in the skillet.

Finely dice the 250 g peeled onion and add it to the bacon and the fat remaining in the skillet. Cook over medium heat for 8–10 minutes, stirring, until the onion is soft, translucent and lightly golden in places. Transfer everything in the skillet, including the fat, to the large bowl and let cool for 10–15 minutes, until the bacon and onion are lukewarm, not hot. Prepare the potatoes in the next step during this time so you do not add a separate cooling wait.

Peel the potatoes, weigh out 1500 g and grate them using the very fine, pointed teeth of the grater to make a moist pulp. Transfer to a fine-mesh sieve over a separate bowl to collect all the juice. Press gently with the back of a spoon for 2–3 minutes, only until the juice stops flowing in a stream and starts dripping. Do not squeeze the pulp dry: it should remain moist and soft, without a puddle of liquid.

Lift the sieve off the bowl of juice and leave the collected juice to stand for 5 minutes so the whitish starch settles at the bottom. Meanwhile, measure out 30 g flour, 6 g salt, 2 g pepper and 2 g marjoram, and beat the 2 eggs in a separate small bowl. Slowly pour off and discard the liquid above the sediment, leaving all the wet starch at the bottom. Save all the recovered sediment to combine with the potatoes in the next step; do not replace it with extra flour or packaged starch.

Check that the bacon, onion and fat in the large bowl are lukewarm; do not combine the mixture with the eggs while it is hot. Add the drained potatoes, all the reserved wet starch sediment, the beaten eggs and the measured flour, salt, pepper and marjoram. Mix thoroughly with a spoon until the ingredients are evenly distributed. The mixture should be thick, moist and spreadable with a spoon, without a separate layer of juice; transfer it straight to the pan in the next step.

Transfer the mixture to the greased pan. Spread in an even layer about 3–4 cm thick and smooth the surface with the back of a spoon, without pressing down firmly. Spread the remaining 10 ml oil thinly over the top. Place the pan straight in the preheated oven without adding any other layers or ingredients.

Bake without covering for 80–90 minutes at 180°C on the middle rack. The top and edges should be golden brown, and the center should be set, firm and slightly springy when pressed gently. A thin knife inserted into the very center down to the bottom should come out without raw, liquid potato mixture, although it may still be moist. If the center is still loose, bake for about another 10 minutes and check again; once the top is deeply browned, cover it loosely with aluminum foil. Do not finish baking based only on the color of the crust.

Remove the pan from the oven and set it on a heatproof trivet. Leave the bake in the pan without covering for 15 minutes so the mixture firms up before cutting. During this time, the edges will pull slightly away from the pan and the portions will keep their firm shape more easily.

After the 15-minute rest, cut the bake in the pan into 6 equal rectangular portions. Lift out each portion with a wide spatula, keeping the browned top and firm center intact, and transfer to plates. Serve while still hot, with one portion per person.