Swabian Onion Tart with Caraway and Creme Fraiche
This Swabian onion tart showcases slowly caramelized onions bound with a creamy egg and creme fraiche custard, aromatic with caraway seeds, baked on a prepared pizza crust. The result is savory, slightly sweet, and deeply comforting—a rustic German classic that balances richness with the gentle bite of cayenne and caraway. Serve warm or at room temperature as an appetizer, light lunch, or alongside soup. This version streamlines the traditional recipe by using convenient prepared pizza dough, making an otherwise labor-intensive dish accessible for weeknight entertaining.
Ingredients
- 4 lb white onions, peeled and sliced
- 8 tbsp butter, divided
- kosher salt, to taste
- cayenne pepper, to taste
- 1 cups creme fraiche, cold
- 2 eggs, large
- ⅛ oz caraway seeds, wholefennel seeds1:1aromatics
warmer licorice note
- 1 prepared pizza crust, room temperatureflaky pie crust1:1bases
richer, more buttery
- butter, for drizzling
- 1 pinch fresh chives, chopped
Instructions
- 1
Saute onions in butter until lightly caramelized.
- 2
Season sauteed onions with salt and cayenne pepper.
- 3
Whisk together creme fraiche, eggs, and caraway seeds in a separate bowl.
- 4
Cool egg mixture to room temperature, then adjust seasoning.
- 5
Fold onions into egg mixture until combined.
- 6
Spread onion mixture evenly over pizza crust.
- 7
Drizzle lightly with butter.
- 8
Bake at 375°F until cream mixture sets and onions are heated through.
- 9
Cool slightly, cut into portions, and garnish with fresh chives.
Tips
Low and slow caramelization takes 30-40 minutes; resist high heat to avoid burning butter and developing bitter flavors.
Room-temperature egg mixture prevents curdling when combined with hot onions; whisk gently to avoid deflating the custard.
Test doneness by inserting a knife near the center; it should come out clean with no runny custard pooling.
Good to Know
Cover tightly and refrigerate up to 3 days. Reheat gently at 160 degrees C until warmed through.
Caramelize onions up to 1 day ahead and store refrigerated. Prepare custard filling same day, assemble and bake just before serving.
Serve warm or at room temperature with a simple green salad and dry Riesling or light beer.
Common Mistakes
Use medium-low heat when caramelizing to avoid blackened, acrid onions.
Cool egg mixture thoroughly to prevent scrambled texture when combined with onions.
Do not overbake; stop when custard center is barely set to avoid rubbery, curdled filling.
Substitutions
Dairy-Free Swaps
General Alternatives
richer, more buttery
herbaceous, heartier
FAQ
Can I make this ahead and freeze?
Baked tart can be cooled, wrapped, and frozen up to 2 months. Thaw overnight in the refrigerator and reheat gently at 160 degrees C until warmed through. The crust may soften slightly upon thawing.
What if I cannot find crème fraîche?
Substitute with equal parts sour cream or Greek yogurt mixed with a touch of heavy cream for slight tang and creaminess. American sour cream works but results in sharper flavor.
How long does this keep at room temperature?
Safely for 2 hours maximum due to eggs and dairy. Beyond that, refrigerate immediately. Do not leave in direct sun or warm kitchen for extended periods.