90min 4 ppl
Tuna Boulangère
91 minutes
4 people
Hardover 60 min or 12+ steps
91 min · 10 steps
Hard: over 60 min or 12+ steps
610 kcalper person
Protein 52g
Carbs 38g
Fats 24g
About this dish
Thick tuna steaks are seared hard to build a deep crust, then finished over a slow-roasted boulangère of waxy potatoes and onions that have drunk up fish stock and thyme — the same technique Basque cooks use to keep the fish succulent while the potatoes turn silky and golden at the edges.
Allergy Info
Dairy, Sulphites, Fish
Diet Info
Pescatarian
Ingredients
Fresh Produce
- Waxy potatoesCharlotte or Ratte, peeled and sliced 3mm thin900 g
- White onionspeeled and finely sliced into half-moons3 medium
- Garlic clovesthinly sliced4 cloves
- Fresh thyme6 sprigs
- Fresh bay leaves2 whole
- Flat-leaf parsleyfinely chopped1 tbsp
- Lemoncut into wedges to serve1 whole
Fish & Seafood
- Tuna steaks (pavés)at least 3cm thick4 x 200g
Dairy & Eggs
- Unsalted butter30 g
Tins & Jars
- Fish stockgood-quality350 ml
Spices & Seasonings
- Flaky sea saltdivided1 tsp
- Freshly ground black pepperdivided1 tsp
Oils & Condiments
- Dry white wine100 ml
- Extra-virgin olive oildivided4 tbsp
Utensils
- Mandoline
- Oven-safe sauté pan or gratin dish
- Heavy cast-iron or stainless-steel skillet
- Instant-read meat thermometer
Method
1
Peel and slice the potatoes to 3mm on a mandoline or with a sharp knife. Slice the onions and garlic. Pat the tuna steaks completely dry with paper towels and season both sides with half the salt and pepper. Set everything aside at room temperature while you begin the boulangère.
Approx. 12 minutes
2
Preheat the oven to 180°C, or 160°C for a fan oven, or gas mark 4. Heat 2 tablespoons of olive oil and the butter in a large oven-safe sauté pan or gratin dish over medium heat. Add the onions and garlic and cook, stirring occasionally, for 12–15 minutes until completely soft and pale golden but not browned.
Approx. 14 minutes
3
Add the white wine and let it bubble for 2 minutes until reduced by half, scraping the base of the pan.
Approx. 2 minutes
4
Layer the sliced potatoes over the softened onions, tucking in the thyme sprigs and bay leaves as you go. Pour over the fish stock — it should come about halfway up the potatoes. Season with the remaining salt and pepper.
Approx. 4 minutes
5
Cover tightly with foil or a lid and transfer to the oven for 35 minutes, until the potatoes are just tender when pierced with a knife tip.
Approx. 35 minutes
6
Remove the foil and return to the oven for a further 15 minutes until the top layer of potato is lightly golden and most of the stock has been absorbed, leaving the base moist but not soupy.
Approx. 15 minutes
7
While the boulangère finishes its uncovered roast, heat the remaining 2 tablespoons of olive oil in a heavy cast-iron or stainless-steel skillet over the highest possible heat until the oil is just beginning to smoke.
Approx. 2 minutes
8
Lay the tuna steaks in the pan and sear, without moving them, for 90 seconds until a deep mahogany crust has formed on the underside.
Approx. 2 minutes
9
Flip the steaks and sear the second side for 60–90 seconds. Use an instant-read meat thermometer and pull the tuna at 54°C for a medium-rare centre, or continue to 63°C for fully cooked through — either is safe, so cook to whichever doneness you prefer.
Approx. 2 minutes
10
Remove the bay leaves and thyme stalks from the boulangère. Nestle the seared tuna steaks on top of the potatoes, scatter over the parsley, and serve straight from the dish with lemon wedges alongside.
Approx. 3 minutes
