Préfou is the Vendée's stuffed baguette, and it is the fastest good thing you can make with a block of Bordier butter. Two baguettes get split lengthwise, spread thickly with Roscoff onion butter, layered with prosciutto, and closed back up. A short spell in the freezer firms everything so it slices cleanly, then fifteen minutes in a hot oven does the rest. Hands-on time is roughly a quarter of an hour, and the slices come out crackling at the edges with a molten, oniony center.
At a glance
- Difficulty: Easy
- Serves: Makes 1 préfou from 2 baguettes, enough for a table of six to eight at cocktail hour
- Active time: About 15 minutes, plus 15 minutes in the freezer. Bordier does not state a prep time, so this is our estimate.
- Cook: 15 minutes at 210°C / 410°F
- Key ingredient: Bordier Roscoff Onion Butter
Why this works
Bordier's Roscoff onion butter dates to 2016, after Jean-Yves Bordier met the Johnnies of Roscoff, the Breton onion growers who once crossed the Channel by boat and sold braids of pink onions door to door. The butter carries pink AOP Roscoff onion, a variety that is sweeter and far less aggressive than a standard yellow onion, worked into butter churned by hand on a wooden malaxeur in Brittany. That sweetness is the whole trick here. You get the depth of slowly cooked onions without cooking a single one.
The freezer step is not optional, and it has nothing to do with chilling the bread for its own sake. A soft baguette packed with room-temperature butter tears when you cut it, and the filling smears. Fifteen minutes in the freezer firms the butter just enough that a serrated knife passes through crust, crumb, butter, and ham in one clean stroke. The slices then go into a hot oven still cold, so the outside crisps before the butter has finished melting out of the middle. That contrast, brittle edge against molten center, is what separates préfou from ordinary garlic bread.
Ingredients
Enough for one préfou built from two baguettes. Bordier's quantities are below, with US measures alongside.
| Ingredient | Metric | US |
|---|---|---|
| Baguettes | 2 | 2 |
| Bordier Roscoff onion butter | 100 g | 3½ oz |
| Prosciutto | 5 slices | 5 slices |
Method
Step 1: Fill the baguettes
Split each baguette in two lengthwise. Spread the bottom half with the Roscoff onion butter, going right to the edges, then lay the prosciutto slices over the butter.
Step 2: Wrap and freeze
Set the top half back in place. Wrap each loaf individually, roll it in plastic wrap, and freeze for 15 minutes. Meanwhile, heat the oven to 210°C / 410°F (gas mark 7).
Step 3: Slice and bake
Take the baguettes out of the freezer, unwrap them, and cut into 1.5 cm / ¾ inch slices. Bake for 15 minutes and serve warm, with drinks for example.
Tips from our kitchen
- Take the butter out early. Bordier butter spreads best at around 18°C / 65°F. Straight from the refrigerator it will tear the crumb; let the block sit on the counter for 30 to 45 minutes and it will spread like frosting.
- Do not skimp on the layer. 100 g across two baguettes sounds generous and it is meant to. A thin scrape disappears in the oven and you lose the molten center that makes this dish.
- Use a serrated knife and a sawing motion. Pressing down on a cold, filled loaf crushes it. Long strokes with a bread knife keep the slices intact.
- Bake on parchment, not a bare sheet. Butter will run out of the cut faces. Parchment catches it, and you can spoon the browned drippings back over the slices before serving.
- Watch the last three minutes. At 210°C / 410°F the line between golden and bitter is short. Pull the tray when the edges are deep gold and the butter is bubbling, not when the tops have gone dark.
- Freeze ahead if you want. The assembled, wrapped loaves hold for a few weeks in the freezer. Slice from frozen and add two or three minutes to the bake.
How to serve it
Préfou belongs on a table with drinks rather than at the start of a sit-down meal. Pile the warm slices in a bowl or on a wooden board and put them out with a dry white, a Muscadet or a Sancerre, and something briny to cut the richness. Tinned mussels or mackerel work beautifully next to the onion butter, and our guide to La Brújula Spanish conservas covers which tins to reach for. Anything left over reheats well the next day in a hot oven for five minutes.
Where to buy Bordier Roscoff Onion Butter in the US
The French Pantry ships Bordier butter across the United States in insulated overnight packaging, straight from the workshop in Brittany.
- Churned Roscoff Onion Butter by Bordier (4.4 oz): pink AOP Roscoff onion folded into hand-churned Breton butter, sweet rather than sharp.
If you want to work through the rest of the range, browse the Maison Bordier collection.
Frequently asked questions
How much Bordier butter do I need to buy?
Our blocks are 4.4 oz / 125 g. The recipe calls for 100 g / 3½ oz, so a single block covers it with a little left over for toast the next morning.
Can I use a different Bordier butter?
Yes. Espelette pepper butter turns it warm and gently spicy, and wild garlic and Kampot pepper butter is the closest thing to a classic garlic bread. Salted butter works too if you add your own aromatics, though you lose the sweetness that makes the Roscoff version distinctive.
What if I cannot find prosciutto?
Any thinly sliced dry-cured ham does the job. Bayonne ham is the more French choice, and Spanish serrano is fine. A vegetarian version with no ham at all is still very good, since the butter is doing most of the work.
How should I store the butter?
Keep it wrapped in the refrigerator and use it within about two weeks of opening. Butter picks up odors quickly, so keep it away from strong cheese and cut onions. It also freezes well for a few months if you wrap it tightly.
Does Bordier butter need refrigeration?
Yes. Bordier butter is a fresh, hand-churned product and ships cold. Move it to the refrigerator as soon as it arrives, and only bring out what you plan to use in the next hour or so.
Can I make this in advance?
Assemble and wrap the loaves up to a day ahead and keep them in the refrigerator, or freeze them for longer. Slice and bake just before serving, since préfou is at its best straight from the oven.
Related reading
- Bordier Butter: What It Is, Why Chefs Love It, and How to Use It
- How to Choose Your French Butter: A Buyer's Guide
- Paysan Breton: The Breton Butter Guide
Recipe and photograph adapted from Maison Bordier, with thanks. The French Pantry is an authorized US retailer of Bordier butter.