Reuben Sandwich with homemade tomato paste

👨‍🍳 Method

For the homemade tomato paste ✓ Homemade · or skip – back to store-bought

1. 1
   Wash the tomatoes, remove the cores and quarter each tomato.

   KnifeCutting board
2. 2
   Put the tomatoes, the salt and half of the olive oil in a wide pot, cover and cook over medium heat about 20 minutes, until the tomatoes soften and release their liquid.

   StoveWide, shallow pot
3. 3
   Pass the tomatoes and their liquid through a food mill or sieve and return the purée to the pot: the skins and seeds stay behind.

   Food millorFine sieve
4. 4
   Cook uncovered about an hour at a lively simmer, stirring now and then, until the purée reduces by half.

   StoveWooden spoon

   💡The paste burns easily as it dries: stir and scrape the bottom and edges, and once it is thick, don't walk away.
5. 5
   Preheat the oven to 110°C (230°F).

   Oven

   💡Put things in the oven only once it's reached temperature, after the heating light has gone off: an oven that hasn't reached temperature changes baking times, and the bake burns outside or stays underbaked.
6. 6
   Grease a wide baking dish with the rest of the olive oil and pour in the purée in a thin layer. Dry in the oven about 3 hours, stirring and scraping the edges every 30 minutes, until the paste is thick, sticky and brick red.

   OvenBaking sheetSilicone spatula
7. 7
   Let the paste cool.

   Jar

For the Hot Sandwich

1. 8
   Spread the butter on the outside of slice the bread.

   💡The butter goes on the outside, the side that meets the pan: it's what gives the bread its golden, crisp crust.
2. 9
   Mix the mayonnaise and tomato paste into a sauce and spread it on the inside of slice the bread.
3. 10
   Place the yellow cheese, meat and sauerkraut on half of slice the bread and cover each one with another slice, buttered side out.
4. 11
   Heat a heavy pan over medium heat.

   StoveFrying pan
5. 12
   Grill the sandwiches 3 minutes per side, until the bread is golden and crisp and the cheese has melted completely.

   StoveFrying panSilicone spatula

   💡Medium heat, not high: the bread browns at the same pace the cheese melts, while over high heat it burns outside before the cheese inside melts.
6. 13
   Cut on the diagonal.

   KnifeCutting board