Zwiebelkuchen, German Onion Cake, is a savory tart with a biscuit like crust topped with grilled onions in a creamy filling.
1/4cupcornstarch (or arrowroot)
Preheat oven to 450 degrees. Lightly grease a 9 x 13 baking pan.
Chop bacon into small pieces and cook in a large skillet over medium heat until cooked, but not crispy, about 5 minutes. Use a slotted spoon to remove the cooked bacon and set on paper towels to drain.
While bacon is cooking, thinly slice onions. Add sliced onions to the bacon grease after removing the cooked bacon pieces. Cook until just turning brown, about 10 minutes. Add marjoram and pepper. Remove from heat.
In a mixing bowl, whisk together flour, cornstarch, baking powder and salt. Cut in shortening with a pastry blender or two knives until it is the texture of soft crumbs.
Add the milk and mix together into a soft dough. Add additional milk if the dough seems dry.
Spread dough into the pan, pressing a little up the sides. Top with cooked onions. Quickly beat together egg and sour cream and spread on top of onions. Finally sprinkle with cooked bacon pieces.
Bake at 450 degrees until the center is set, about 15-20 minutes. Let cool 5-10 minutes then cut in slices and serve.
German Onion Cake (Zwiebelkuchen) https://thatrecipe.com/blog/zwiebelkuchen-german-onion-cake-an-old-world-treat-ourfamilytable/