Sour Cream & Caramelized Onion Galette
Sour Cream & Caramelized Onion Galette! is a medium British recipe that serves 6. 250 calories per serving. Recipe by justine_snacks on YouTube.
Prep: 20 min | Cook: 1 hr | Total: 1 hr 35 min
Cost: $6.60 total, $1.10 per serving
Ingredients
- 2 medium Yellow Onion (thinly sliced)
- 1 tablespoon Fresh Rosemary (finely chopped)
- 1 teaspoon Kosher Salt (adjust to taste)
- 0.5 teaspoon Black Pepper (freshly ground)
- 1 cup Sour Cream (full‑fat, chilled)
- 2 tablespoons Olive Oil (extra‑virgin)
- 1 sheet Puff Pastry Sheet (thawed if frozen, about 250 g)
- 1 large Egg (beaten, for egg wash)
Instructions
Slice the Onions
Trim the ends of the onions, halve them, and slice thinly (about 1‑2 mm) using a chef's knife on a cutting board.
Time: PT5M
Caramelize the Onions
Heat 2 Tbsp olive oil in a large skillet over medium‑low heat. Add the sliced onions, chopped rosemary, salt, and pepper. Cook, stirring occasionally, for about 30 minutes until the onions are deep golden, soft, and sweet‑smelling.
Time: PT30M
Temperature: Medium‑low
Incorporate Sour Cream
Reduce heat to low and stir in 1 cup sour cream. Continue cooking for 5 minutes, allowing the sour cream to thicken and caramelize further, creating a glossy filling.
Time: PT5M
Temperature: Low
Prepare the Pastry
While the onions finish, preheat the oven to 200°C (392°F). Roll out the puff pastry sheet on a lightly floured surface and fit it into the tart pan, trimming excess. Prick the base with a fork.
Time: PT10M
Temperature: 200°C
Assemble the Tart
Spread the caramelized onion‑sour cream mixture evenly over the pastry base, leaving a small border.
Time: PT2M
Egg Wash
Brush the exposed pastry edge with the beaten egg to promote a golden finish.
Time: PT1M
Bake the Tart
Place the tart in the preheated oven and bake for 25 minutes, or until the pastry is puffed, golden brown, and the filling is set.
Time: PT25M
Temperature: 200°C
Cool and Serve
Remove the tart from the oven and let it rest for 10 minutes before slicing and serving.
Time: PT10M
Nutrition Facts
- Calories
- 250
- Protein
- 5 g
- Carbohydrates
- 20 g
- Fat
- 15 g
- Fiber
- 2 g
Dietary info: Vegetarian, Contains dairy, Contains gluten
Allergens: Dairy, Gluten, Egg
Ingredient Substitutions
- Instead of Yellow Onion: White onion, Sweet onion
- Instead of Fresh Rosemary: Dried rosemary (1 tsp)
- Instead of Kosher Salt: Sea salt
- Instead of Black Pepper: White pepper
- Instead of Sour Cream: Greek yogurt, Crème fraîche
- Instead of Olive Oil: Unsalted butter
- Instead of Puff Pastry Sheet: Homemade shortcrust pastry
- Instead of Egg: Milk wash
Equipment Needed
- Chef's Knife
- Cutting Board
- Large Skillet
- Wooden Spoon
- Mixing Bowl
- Tart Pan or Baking Sheet
- Pastry Brush
- Oven
Critical Steps — Do Not Skip
- Caramelizing the onions slowly to develop deep flavor without burning.
- Stirring in sour cream over low heat to prevent curdling.
- Ensuring the puff pastry is fully baked to avoid a soggy crust.
Chef Tips from the Video
- For extra richness, replace half the olive oil with unsalted butter when caramelizing.
- A splash of balsamic vinegar added with the sour cream deepens the caramel flavor.
- Use cold butter chunks in the puff pastry for maximum flakiness.
Troubleshooting
Onions burned or stuck to the pan.
Reduce heat to medium‑low, add a splash of water, and stir frequently. Use a non‑stick skillet if needed.
Sour cream curdles when added.
Lower the heat before adding sour cream and stir continuously. If curdling occurs, whisk in a tablespoon of milk to smooth it out.
Pastry is soggy after baking.
Ensure the pastry base is well‑pricked, bake on a preheated baking sheet, and avoid over‑filling. If needed, bake the crust alone for 5 minutes before adding the filling.
Storage
Refrigerator: Store leftovers in an airtight container for up to 3 days.
Freezer: Not recommended; pastry becomes soggy after thawing.
Room temperature: Can sit at room temperature for up to 2 hours.
Make-Ahead Tips
- Caramelize the onions and mix with sour cream up to 2 days ahead; store in the fridge and reheat briefly before assembling.
- Prepare the pastry crust and keep it chilled; assemble just before baking for best puff.
Frequently Asked Questions
What is the cultural significance and history of caramelized onion and sour cream tart in British cuisine?
Savory tarts have long been a staple of British pub and home cooking, often filled with seasonal vegetables and rich dairy. The combination of caramelized onions and sour cream reflects a modern twist on classic British pastry, offering a comforting, hearty flavor that echoes the country’s love for buttery crusts and deep, sweetened fillings.
What are the traditional regional variations of onion tarts in the United Kingdom?
In Scotland, onion tarts may include oatmeal or whisky in the crust, while in England you’ll find versions with cheese and herbs like thyme. Some Welsh recipes add leeks instead of onions, and the Isle of Wight often incorporates local cider for a subtle tang.
How is a caramelized onion and sour cream tart traditionally served in Scotland?
It is typically served warm as a snack or light meal, sliced into wedges and accompanied by a simple green salad or a dollop of extra sour cream. In Scottish pubs it may be paired with a pint of ale.
What occasions or celebrations is this tart associated with in British culture?
Savory tarts are popular at tea parties, garden gatherings, and holiday buffets such as Christmas or Easter brunches. Their handheld size makes them ideal for cocktail parties and casual get‑togethers.
What other British dishes pair well with caramelized onion and sour cream tart?
Serve it alongside a classic cucumber and mint salad, roasted root vegetables, or a hearty pea soup. A glass of crisp English cider or a light ale complements the rich, buttery flavors.
What are the most common mistakes to avoid when making caramelized onion and sour cream tart?
The biggest errors are cooking the onions on too high a heat, which burns them, and adding sour cream before the onions are fully softened, which can cause curdling. Also, under‑baking the pastry leads to a soggy crust.
Why does this recipe use sour cream instead of heavy cream for the tart filling?
Sour cream adds a pleasant tang that balances the sweetness of the caramelized onions, and its lower fat content allows it to thicken and caramelize without becoming overly greasy, creating a richer flavor profile than plain heavy cream.
Can I make the caramelized onion and sour cream tart ahead of time and how should I store it?
Yes. Caramelize the onions and mix with sour cream up to two days in advance, storing in the refrigerator. Assemble the tart just before baking; leftovers can be refrigerated for up to three days and reheated in the oven.
What texture and appearance should I look for when the tart is done cooking?
The puff pastry should be golden‑brown, puffed, and crisp. The filling should be set, glossy, and slightly caramelized on top. When pressed lightly, the center should feel firm, not liquid.
What does the YouTube channel justine_snacks specialize in?
The YouTube channel justine_snacks focuses on quick, approachable vegetarian and snack‑style recipes, often highlighting comfort foods with creative twists and easy‑to‑follow tutorials for home cooks.
How does the YouTube channel justine_snacks' approach to British comfort food differ from other cooking channels?
justine_snacks emphasizes minimalist ingredient lists, budget‑friendly sourcing, and personal storytelling, turning classic British comfort dishes into snack‑sized, vegetarian-friendly versions that appeal to a younger, health‑conscious audience.
Last updated: August 20, 2026
