Savory French Onion Sausage Rolls

If you love the deep, cozy flavor of French onion soup — that sweet caramelized onion goodness with a little thyme and richness — these sausage rolls are about to become your new favorite thing. They’re the kind of snack that feels fancy without being fussy: flaky puff pastry on the outside, and a juicy, savory sausage filling on the inside, studded with golden onions that taste like they’ve been cooking all day.

They’re perfect for parties (they disappear fast), but honestly? They’re just as wonderful on a quiet night with a simple salad and something warm to drink. As they bake, the pastry puffs up and turns golden, and the kitchen starts smelling like buttery onions and herbs — the kind of smell that makes people “just happen” to walk by the oven.

Ingredients

For the Onion Filling:

2 tablespoons butter
2 large yellow onions, thinly sliced
1 teaspoon sugar
1/2 teaspoon salt
1/4 teaspoon black pepper
1/2 teaspoon thyme (dried or fresh)
1 teaspoon balsamic vinegar (optional, for depth)

For the Sausage Mix:

1 pound (450 g) pork sausage meat (or sausage casings removed)
1/2 cup breadcrumbs
1 egg
1 tablespoon Dijon mustard
1/4 cup grated Gruyère or Swiss cheese (optional)
Salt and pepper, to taste

For Assembly:

1 sheet puff pastry, thawed
1 egg yolk + 1 tablespoon milk (egg wash)
Optional: sesame seeds or dried thyme for topping

Instructions

Caramelize the onions.
Melt the butter in a skillet over medium heat. Add the sliced onions, sugar, salt, pepper, and thyme. Cook for 20–25 minutes, stirring now and then, until the onions are deeply golden and sweet.
If you’re using balsamic vinegar, stir it in at the end. Then let the onions cool — warm onions can make the pastry harder to work with.
Preheat and prep.
Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
Make the sausage filling.
In a large bowl, mix together the sausage meat, breadcrumbs, egg, Dijon mustard, cheese (if using), and the cooled caramelized onions. Stir until it’s evenly combined — it’ll smell amazing already.
Roll out and cut the pastry.
Lightly flour your surface and roll the puff pastry into a rectangle if needed. Cut it lengthwise into two long strips.
Form the rolls.
Divide the sausage mixture in half. Shape each half into a long log down the center of each pastry strip. Fold the pastry over the filling and press the edge to seal (a dab of water helps).
Flip seam-side down, then slice into about 2-inch rolls.
Egg wash and bake.
Arrange the rolls on your baking sheet. Brush the tops with egg wash and sprinkle with sesame seeds or a pinch of thyme if you’d like.
Bake for 20–25 minutes, until puffed and golden brown.
Cool slightly and serve.
Let them cool for a few minutes before serving — the filling will be hot and juicy.

Presentation Tips

Pile these on a serving board or platter and tuck a small bowl of grainy mustard on the side for dipping. A sprinkle of fresh thyme over the plate makes them look extra “bistro-style.” If you’re serving them for dinner, add a crisp green salad with a tangy vinaigrette to balance the richness — it’s such a nice pairing.

Conclusion

These Savory French Onion Sausage Rolls are flaky, rich, and packed with that sweet-onion, herby goodness that makes French onion flavor so irresistible. They feel a little upgraded and special, but they’re still easy enough to make whenever the craving hits. Bake a batch soon — whether it’s for guests or just for you — and don’t be surprised if they become your go-to “one more won’t hurt” snack.