Hake filet topped by crusty potato scales, served on roughly mashed potatoes and with red pepper fondue
Fish topped by a “skin” of crispy potato scales has become a classic of the French cuisine. This was a technique and a dish (Red mullet dressed in crusty potato scales - see picture below) that Paul Bocuse created some decades ago, and that he highly contributed to popularize, the technique I mean, because as far as the dish is, concerned, it would cost you around $90.00 at the Auberge du Pont de Collonges, i.e. chez Monsieur Paul. Which, incidentally, is not that expensive as compared with dishes proposed by non-starred restaurants and requiring much less work. Just saying…
Of course, my intention was not to recreate, or try to recreate, Monsieur Paul’s dish. The artistic presentation with the ferns made with a veal sauce and the red mullet, a tiny and fragile, the short cooking time of which is antinomic to the time required to cook the potato scallops were a challenge that I was not (yet?) prepared to. I just wanted to use his technique of crusty potato scales on a less tiny fish, although flaky hake is not really the ideal fish. But this is what I had, and I love hake. That said and although it looks spectacular, it is also much less difficult than it seems. But what I realized is that the look is not the most important thing achieved here. This is where you recognize great chefs. The first reason why Bocuse cooked his red mullets that way was, in my opinion, not to look pretty, and it does, but to cook efficiently. The potato skin protects the fish and avoids overcooking it. A bit, a lot in fact, like the technique a BBQ-grilling a non-scaled fish. The scales, either the natural ones or the potato ones, form an armor against the heat… This is a technique of cooking before being an eye-catching trick. Brilliant!!!
I used hake, but almost any other white fish could be cooked that way. If the red mullet is possibly the most technical fish to cook, in scales and intrinsically, but it could be made with fillets of cod, branzino, turbot, snapper, grouper, halibut… and the easiest fish to cook this way is probably the seabass, given its density and its thickness.
I served the hake fillets on fork-mashed potatoes mixed with olives and roasted red peppers, with a red pepper fondue and a red pepper coulis.
Levels of difficulty
For the fish:
§ 2 hake fillets
§ 3 or 4 small (around 1” diameter) new potatoes (for the scales)
§ 1 tbsp. of olive oil
§ Melted butter
§ 1 egg white
§ Pepper or Piment d’Espelette
§ A couple of sage leaves (or any other relevant herbs)
§ Parchment paper
§ A non-stick frying pan or a crêpe pan
For the sides
§ 1 Russet potato
§ 1 red (here) bell pepper
§ 1 or 2 garlic cloves
§ Rub salt the hake fillet and place them in the fridge. This is a classical technique used before grilling or frying fish, and it is particularly relevant here to firm them up.
§ Slice the potatoes very thinly (1 mm) with a mandolin. Personally, I didn’t peel those new potatoes are their skin was very thin and I didn’t caliber them with a cookie cutter for instance as they were of a quite regular shape and I used the smaller scallops for the fish narrower parts.
§ Do not rinse the potatoes (you want to keep the starch as a “cement”) and soak them gently in the melted butter with the white egg and pepper (no salt as the fish is already salted).
§ Take the fish out of the fridge, rub away the salt in excess (but don’t rinse the fish), and place the scales one by one, after dropping the extra butter, so that they overlap each other of around 50%, width- and length-wise.
§ Cut a parchment paper sheet slightly exceeding the size of the fish, place it on top of the scales, and very gently press with your hand to “stick” the sales together
§ Heat some olive oil over medium/low burner (4/5)* in a non-stick frying pan**, and when the oil is hot enough, flip over the steak fillet so that the parchment paper is at the bottom and, using an adapted spatula, delicately place the fillet in the pan
§ Let it cook for 5 or 6 minutes* till your potato scales get the appropriate color (lift up a corner of your potato crust to have a peek on it)
§ Then, place the spatula under the very useful parchment sheet and flip over your fillet on its “naked” side to finish cooking it for 1 or 2 minutes over low burner (2)
§ You just need to serve it with your mashed potatoes and red pepper, or any side you may fancy for, and a nice glass of wine. Personally, I opted for a Chablis, a white Burgundy with green reflections and citrussy notes.
* temperature and time to adjust depending on the fish you cook, its texture and its thickness. The time and temperature I give as an indication are for ~1”thick hake fillet.
** or better, in my case, a crêpe pan, that has lower walls than a normal frying pan, which facilitates the handling (notwithstanding the fact that otherwise, I only have cast iron pans!)