Surf and turf, Breton style: pork tenderloin braised in dry cider, with seaweed butter standing in for the sea. This is a one-pot dish from Maison Bordier. The filet mignon is cut into steaks and cooked gently in Bordier Seaweed Butter, then simmered with cider and unpeeled new potatoes until the potatoes give way. Blanched Brussels sprouts and wild mushrooms finish the plate. Figure on about an hour, most of it unattended.
At a glance
- Difficulty: Medium
- Serves: 4
- Active time: About 25 minutes
- Cook: Until the potatoes are tender, roughly 35 to 40 minutes. Bordier gives no total time for this one.
- Key ingredient: 70 g (2 1/2 oz) Bordier Seaweed Butter
Why this works
Seaweed butter is the one that started it all. Jean-Yves Bordier made it in 1986 after a meal with friends, folding iodised Breton seaweed into butter churned by hand on a wooden malaxeur. It does not taste fishy. It tastes saline and green, closer to a good shellfish stock than to a seasoning, and that is exactly what a pork braise wants. Brittany has been putting the sea and the farmyard on the same plate for a very long time, and this dish is the short version of that idea.
Here the butter is the cooking fat rather than a finishing touch, so its flavour ends up everywhere: in the fond at the bottom of the pot, in the cider as it reduces, and in the potatoes that soak up both. Cooking the pork without browning it is deliberate. Gentle heat keeps the milk solids from catching and keeps the seaweed clean and bright instead of toasted. The cider then brings acidity and a little sweetness, which is what stops a butter braise from turning heavy.
Ingredients
Bordier is loose about quantities for the vegetables. We have kept their wording rather than inventing numbers, and our own suggested amounts are in the tips below.
| Ingredient | Metric | US |
|---|---|---|
| Pork filet mignon (tenderloin) | 400 g | 14 oz |
| Bordier Seaweed Butter | 70 g | 2 1/2 oz |
| Baby new potatoes | A few | A few |
| Brussels sprouts | A few | A few |
| Onion | 1 | 1 |
| Fresh wild mushrooms | Quantity not specified | Quantity not specified |
| Dry cider | 30 cl | About 1 1/3 cups |
| Garlic | 1 clove | 1 clove |
| Dark veal stock (optional) | 2 tbsp | 2 tbsp |
| Salt and pepper | To taste | To taste |
Method
Step 1: Braise the pork with cider and potatoes
Cut the filet mignon into four steaks. Melt the butter in a Dutch oven and cook the pork in it without letting it brown. Season with salt and pepper. Add the sliced onion and shallots along with the crushed garlic clove, and sweat them. Add the potatoes, washed but not peeled. Moisten with the veal stock, if you are using it, and the cider. Simmer slowly over low heat until the potatoes are cooked through. Keep a close eye on the evaporation and add a little more water toward the end if the pot runs dry.
Step 2: Blanch the sprouts, sear the mushrooms, and plate
Blanch the Brussels sprouts in salted water, then drop them into an ice bath to stop the cooking and hold their colour. Set them somewhere warm until you are ready to serve. At the last moment, sauté the mushrooms in the Dutch oven. Plate the pork with the garnish arranged around it.
Tips from our kitchen
- Keep the pan below a sizzle. The instruction to cook the pork "without browning" is the whole technique. Seaweed butter has milk solids and salt in it, and once they catch you get a toasted, nutty flavour that fights the marine note you paid for. Medium-low heat, and let the butter foam gently rather than crackle.
- About those shallots. Bordier's ingredient list names one onion, but the method asks for "sliced onions and shallots." We read that as the onion plus a shallot or two if your kitchen has them. The dish is complete with the onion alone, so it is not worth a second trip to the store.
- Mushroom quantity is not given. Bordier simply says "fresh wild mushrooms." Our guidance for four people is roughly 150 g (5 oz), cleaned with a brush and torn rather than sliced. Chanterelles or hen of the woods are ideal, and cremini will do the job.
- Use dry cider, not sweet. 30 cl is about 1 1/3 cups, near enough one 12 oz bottle. A French cidre brut or a dry American hard cider reduces into something clean and appley. Sweet cider turns the sauce cloying and there is no fixing it afterward.
- Pull the pork if the potatoes need longer. Tenderloin is lean and goes from juicy to chalky quickly. If your potatoes are still firm once the pork is cooked through, lift the steaks out, keep them covered, and slide them back into the pot for the last two minutes to reheat.
- Do not skip the ice bath. Brussels sprouts keep cooking in their own heat and go army green within minutes. Thirty seconds in ice water fixes both the colour and the texture, and they reheat perfectly in the residual warmth of the pot.
How to serve it
This wants bread and the same cider you cooked with. A crusty country loaf is there to mop the pot, and a second block of butter on the table is not excessive: put out a little more seaweed butter alongside plain salted, and let people compare. If you are new to flavoured butter and want to know which ones earn a place in the fridge, our guide to Bordier butter walks through the full range and what each one is actually for.
Where to buy Bordier Seaweed 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 Seaweed Butter by Bordier (4.4 oz): hand-churned Breton butter with iodised seaweed, the original Bordier flavoured butter and the one this braise is built on.
If you want to try the rest of the range, browse the Maison Bordier collection.
Frequently asked questions
How much Bordier Seaweed Butter do I need for this recipe?
The recipe calls for 70 g, and a Bordier block is 125 g (4.4 oz). One block covers it with a little over half a block left for the table.
Can I substitute a plain butter?
You can cook the dish in Bordier Salted Butter and it will be very good, but it becomes a different dish. The seaweed is what makes it surf and turf rather than a cider braise. If you go that route, a splash of the mussel or clam liquor you happen to have does some of the same work.
Does it have to be pork tenderloin?
Filet mignon de porc is the French cut, and US pork tenderloin is the direct equivalent. Cut 400 g into four steaks roughly 3 cm thick and the timings hold.
How should I store the butter once it is open?
Keep it wrapped in its paper in the coldest part of the fridge and use it within about two weeks. Flavoured butter picks up other smells fast, so an airtight box is worth it. It freezes well for up to three months if you wrap it tightly.
Does Bordier butter need refrigeration?
Yes. Bordier butter is a fresh, hand-churned product and ships cold in insulated overnight packaging. Move it to the fridge as soon as it arrives.
Can I make this ahead?
The braise reheats well, so cook it a day ahead and warm it gently. Hold back the mushrooms and the sprouts and finish those at the last minute, otherwise both go soft.
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.