Apple - Red Onion - Flammkuchen

Cooking healthy meals has been a priority for me lately. Today's recipe I got out of Schrot & Korn's  Apple - Red Onion - Flammkuchen Since it's in German, here is the English recipe (all copy rights remain with Schrot & Korn):

For guests · For 4–6 servings
Prep time: 30 min. + Standing / Baking time
Calories per portion: 445 kcal;
19 g fat, 12 g protein, 57 g total carbs

400 g flour
20 g yeast
1½ tbsp sugar
1 tsp salt
2 tbsp vegetable oil
2 sour apples (appropriate for baking, organic)
2 small red onions
50 g hazelnuts
100 g crème fraîche (if you can't find in your area, substitute with sour cream)
100 g goat's cream cheese
salt, pepper
5 twigs thymes
10 sage leaves

  1. Sieve the flour in a bowl, create an indentation. Dissolve the yeast with some warm and a teaspoon of sugar. Cover the bowl and let stand in a warm place.  (For example, I place my covered Tupper(c) bowl in a sink of warm water.) 
  2. After 10 minutes add 200 ml of warm water, salt and oil to your pre-dough and mix with the dough hook of your hand mixer. 
  3. Knead the dough manually, then cover again and let it rise until it has approximately doubled in volume. 
  4. Use a apple corer, then thinly slice the apples with skin on.  Mix the apples with 1 tbsp sugar. Slice the red onions in rings or slices. Roughly chop the hazelnuts.
  5. Knead the dough on a floured surface. Roll the dough out into the shape of your baking sheet/pans. My sheet in Germany is 33cm x 41cm. Place on the greased baking sheet. I let the dough rise for a few moments to heal the patched portions of my results. Spread the crème fraîche on the dough, leaving the edges free. Place apple and onion slices on the dough, also the goat's cream cheese. Salt and pepper. Spread the chopped nuts (I substituted with almond slices, because I had no hazelnuts on hand.) Put the sheet for approx.  20 minutes in the oven at 220°C (ca. 430°F)
  6. Pluck fresh thyme leaves and chop sage leaves to spread on the Flammkuchen. Serve immediately.