Reuben Sandwich with homemade sauerkraut and homemade mayonnaise

👨‍🍳 Method

For the Hot Sandwich

1. 1
   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. 2
   Put the egg, mustard, salt and black pepper in the blender jar and blend about half a minute.

   BlenderorStick blenderorFood processor
3. 3
   Add the oil in a thin, slow stream, while the blender is running, until a thick emulsion forms.

   Blender

   💡The thin stream is everything: fat that goes in too fast can't bind, and the sauce breaks. For mayonnaise and hollandaise, if this happens, start with a fresh yolk and slowly add the broken sauce to it; if the sauce is too thick, thin it with a teaspoon of water.
4. 4
   Add the lemon juice and stir. Taste and adjust the seasoning.
5. 5
   Mix the mayonnaise and tomato paste into a sauce and spread it on the inside of slice the bread.
6. 6
   Remove the outer leaves of the cabbage.
7. 7
   Slice the cabbage into thin ribbons.

   KnifeCutting board
8. 8
   Put the cabbage in a large bowl, sprinkle the salt over it and knead by hand for 5 minutes, until the cabbage softens and releases liquid.

   Bowl

   💡Salt at 2–2.5% of the cabbage's weight: less than that and the good bacteria don't thrive and the cabbage may spoil; more and it's too salty and ferments less.
9. 9
   Pack the cabbage tightly into a clean jar, with the liquid it released, until it is completely covered by liquid.

   Jar

   💡All the cabbage must be under the liquid: oxygen is the enemy of fermentation, and a piece sticking out above it can spoil the whole jar.
10. 10
    Close and leave at room temperature, away from the sun, 7–14 days, until the cabbage is as sour as you like.
11. 11
    Move to the fridge.

    Refrigerator
12. 12
    Place the yellow cheese, meat and sauerkraut on half of slice the bread and cover each one with another slice, buttered side out.
13. 13
    Heat a heavy pan over medium heat.

    StoveFrying pan
14. 14
    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.
15. 15
    Cut on the diagonal.

    KnifeCutting board