Belgium and yet another fish stew. Sigh. Waterzooï de Cabillaud. Hard to get excited about this one. And not because it’s Belgian. They have great food in Belgium. No. It’s just—brown prawns, cod, mussels, winkles. Meh. Roberta warned me beforehand that this was not a good dish. On the upside, we got to make an espuma or foam.

Are foams now a little passé? There was a time when I referred to foam as cuckoo spit. That’s what it looked like to me. Foams can add textural nuance to a dish, which helps create multi-layered, interesting food. In terms of techniques, it’s good for me to know how to make foams. I’ve used a siphon or whipped cream maker at home.

Basically the cod was salted for 30 minutes, rinsed then poached. Meanwhile the mussels and winkles were cooked marinière with butter, shallots and white wine. In practical, chef was suspicious of the winkles and gave them a long, long rinse. He warned us we’d know if we had dodgy ones. We’d smell it after cooking them. Our bodies are programmed to detect such things. And wouldn’t you know it. Phooey. My poaching liquor had THAT stink about it—rotting rock pool. That set me back 10 minutes. I had to clean another bunch of mussels and get them poaching. I didn’t add winkles. Brilliant.

In another pan, butter, shallots and white wine were gently heated until the wine evaporated. Fish stock was added with a Bouquet Garni and reduced. Cream was added and brought to the boil, then passed through a chinois and seasoned. Cold butter cubes were stirred in with a whisk. The foam didn’t take long to form. A quick whizz with a hand blender held at the right angle and Bob’s your uncle. No artificial stabilisers or emulsifiers like lecithin, agar agar or gellan gum. Only cream, butter and air. Of course this meant the foam would naturally deflate more quickly.

The fish was served on a bed of leeks, celery and carrots julienned and cooked l’étuvée—in a very small amount of butter and water.

Chef made another dish in demo. Croquettes de Crevettes Grises à l’Ostendaise. Ostende-style brown shrimp croquettes served with deep-fried parsley. Roberta was excited when I mentioned them. Unfortunately (for her) she didn’t get to try them. They were wolfed down by the team. I expected the filling to involve potato but actually it was a super thick velouté. And a great vehicle for other flavours. This has got me thinking. The velouté started with a roux—butter, flour plus a mixture of shellfish stock and milk. Gruyere cheese was melted in. Then an egg yolk, crème fraiche, lemon juice and brown prawns. A latte colour. Creamy smooth. Rich and yummy.

Foam wasn’t built in a day