Frankfurter Kressesuppe

Ingredients

Equipment Needed

• •3 litre heavy saucepan
• •Immersion blender
• •Kitchen scissors for cutting cress
• •Small frying pan for rye croutons

Instructions

1. 1

   Brown rye croutons

   If you're making croutons, melt 1 tablespoon butter in a small pan and fry the diced rye over medium heat until the edges are crisp and dark gold. Stale rye is better here than fresh bread because it has already lost moisture, so it browns instead of going soft. Tip it onto a plate and salt it lightly while the fat still clings.

2. 2

   Sweat the leeks

   Melt the 2 tablespoons butter in a 3 litre pot over medium-low heat, then add the onion, leek, and a pinch of salt. Cook them gently for 6 to 8 minutes until soft and pale, not brown. Browning pushes the soup sweet and muddy; this one needs a clean base so the cress can speak at the end.

3. 3

   Simmer the potatoes

   Add the diced potatoes, stock, and bay leaf, then bring the pot to a steady simmer. Cook 15 to 18 minutes, until the potato breaks easily against the side of the pot. Use floury potatoes, the kind that fall apart when boiled, because their starch thickens the soup without flour. That is the body. No roux needed.

   Keep the stock light and not too salty. The soup reduces a little, and cress wants its salt adjusted at the end, not buried under a cube from the start.
4. 4

   Blend the base

   Remove the bay leaf and blend the soup until smooth with an immersion blender. If it looks too thick, add a small splash of hot stock or water; if it looks thin, simmer it uncovered for a few minutes before the dairy goes in. Fix the thickness now, because once Schmand and cress are in, the pot stays off the hard boil.

5. 5

   Finish with cress

   Take the pot off the heat and let the bubbling stop. Whisk the Schmand with a ladle of hot soup in a bowl, then stir it back into the pot; warming it first keeps the sour dairy from curdling. Stir in the snipped cress, reserving a little for the bowls, and blend for only 5 to 10 seconds, just enough to turn the soup green. Boil it now and you've cooked out the peppery bite. Würzen, Fett, Salz zum Schluss: add lemon juice or vinegar, white pepper, nutmeg, and salt at the end, when you can taste what the cress needs.

6. 6

   Serve at once

   Ladle the soup into warm bowls, spoon a little Schmand through the surface, and finish with the reserved raw cress and rye croutons if you made them. Serve it straight away. A finished cress soup does not sit on the back of the stove waiting for speeches; the green fades and the sharpness goes quiet. Schön ist, was schmeckt.

Chef Tips

• •Buy living trays of Gartenkresse if you can. Cut it just above the roots and use it at once; once snipped, it loses the peppery edge quickly.
• •Use floury potatoes, marked mehligkochend in Germany. Waxy potatoes stay neat in a salad, but here neat is not useful; you want starch in the soup.
• •Save leek greens, onion trimmings, carrot ends, and parsley stems for stock. Simmer them 30 minutes and strain. Weggeworfen wird nichts, and the soup tastes like vegetables instead of powder.
• •Do not hold the finished soup on the heat. Make the potato base ahead if you need to, then add Schmand and cress only when people are ready to eat.
• •In deep winter, make this only if the cress smells sharp and alive. If it smells tired, cook a stored-root soup and wait for the green season. The calendar knows things.

Advance Preparation

• •The potato base can be cooked, blended, cooled, and refrigerated up to 2 days ahead. Reheat it gently, then finish with Schmand and raw cress just before serving.
• •Rye croutons can be fried 1 day ahead and kept in a dry container. Let them cool fully first, or trapped warmth softens them.
• •Do not add the cress in advance. Its colour and bite are the point of the soup, and both fade once it sits in the warm base.

Frequently Asked Questions

Nutrition Information

1 serving (about 445g)