Dom Wilton knows a thing or two about sandwiches. “I’ve dedicated my life to sandwiches, so I think about them a lot,” says the chef, who worked at Stokehouse and Attica before launching his own hospitality business – Hector’s Deli, a backstreet sandwich shop in Richmond that has earned a big reputation for its superlative sambos – in 2017.

A fine example of Wilton’s sandwich-making philosophy is the Umami Bomb Grilled Cheese Sandwich, a delicious dish the chef created for Broadsheet that calls for not one but two types of cheese: the mild Castello Creamy Havarti and the rich Castello Double Cream Brie.

“Havarti is a really good melting cheese,” says Wilton, likening it to “something accessible” like parmesan or Swiss cheese. “It’s super reliable and delicious. The brie makes it super indulgent.” The contrasting qualities of the two kinds of cheese work well together, Wilton says. “One is creamy and soft, and one has a little bit more structural integrity and a little bit more salinity and acidity.”

Two condiments appear in the sandwich: Kewpie mayonnaise and Oomite, a yeasty concoction made in Byron Bay that delivers a punchy hit of umami. The salty-sweet Oomite melts through the cheese as the sandwich is toasting, infusing it with a whack of earthiness. “It’s like a Welsh rarebit when you add Worcestershire sauce – it’s got that same vinegary, dank depth to it,” says Wilton.

For bread, Wilton has chosen a light rye for his umami bomb creation, which “adds some flavour, but it’s not overpowering like a dark rye,” he says. “It gives it an artisanal feel, rather than just slapping it on a soft white grainy bread.”

Wilton has an essential piece of advice for cooks whipping up the sandwich at home: go low and slow. “People always stuff sandwiches up by not giving them enough time to toast,” he says. ”Oil the pan just enough with a little bit of butter, and butter both sides of the bread. Choose the lowest setting so that the cheese has time to properly melt on the inside and the outside gets golden and crisp, rather than burning the outside and having the inside still cold and hard.”

One of this sandwich’s defining features is its versatility. “There are no limits to when this sandwich could be served,” declares Wilton, who recommends it both as a breakfast dish and as “a romantic date-style sandwich, which you could pair really well with booze.” His tips for a matching tipple? “A funky farmhouse-y natural cider, or a good German riesling or a chenin blanc from the Loire in France – something with good structure and enough acidity to cut through.”

Recipe: Umami Bomb Grilled Cheese Sandwich
Serves: 1

60g Castello Creamy Havarti
40g Castello Double Cream Brie
35g caramelised brown onion
5g Oomite (or Vegemite)
30g Kewpie mayonnaise
Pinch of white pepper
25g soft butter (unsalted)
2 slices light-rye bread


Butter outside of bread and set aside. Mix Kewpie, white pepper and Oomite together and set aside. Heat a pan to very hot and lightly caramelise brown onion, being careful to keep some of its crunch. Set aside.

Evenly spread Kewpie mix on the inside of each slice of bread. Grate havarti and roughly tear brie, and load on one slice of bread. Place onions on top of the cheese and sprinkle with flaky salt.

Close and toast for 5 minutes each side until bread is crispy and cheese is melted.

This article is produced by Broadsheet in partnership with Castello.