There is something so beachside about this sarnie, which is perfect for those teas-on-knees nights. ‘Katsu’ is anything crumbed in Japanese, but also means ‘winning’, and you’ll feel like a winner when you smush in mash-up mushy peas, a classic British dish to accompany fish and chips, with a Japanese wasabi twist – PLUS roasted seaweed snacks (from the snack aisle) for bonus crunch.

You can crumb and fry your own smaller fish (like flathead fillets) to cut into ‘fingers’, or head to the freezer aisle for a shortcut. When buying fish fingers for these, aim for the thickest-looking ones, with the usual eye on sustainability ticks and certifications. You also want a ‘door-stopper’ thickness on the bread – a very English term describing bread that’s been sliced real thick, thanks! If you can’t find shokupan (a Japanese milk bread), ask for ‘toast cut’ high-tin, or use brioche or milk buns if you want something a little more spesh than white bread. 

Serves 4
Chop and stir time: 10 minutes
Set and forget time: 20 minutes

INGREDIENTS
16 fish fingers (or 8 homemade crumbed fish fillets)
4 larger-sized iceberg lettuce leaves
1 loaf of shokupan milk bread (or soft white bakery bread), cut into 8 slices about 1.5 to 2 cm thick
Quality butter, for spreading

Mushy pea mayo
1 cup (140g) frozen peas
1/4 cup (75g) Japanese mayonnaise
1 tablespoon pickled ginger liquor
1/4 teaspoon wasabi paste (optional but excellent)

Home stretch
2 tablespoons pickled ginger slices
Lemon juice
10g toasted seaweed snacks

METHOD
Flippin’ fish
Cook the fish fingers according to the packet instructions – I like to pan-fry them in half butter and half oil for extra crunch, which usually only takes 8 minutes, flipping halfway through. If baking, it may take around 15 minutes once your oven is hot. (If using fish fillets, dust them with flour, dip them in beaten egg, coat them in panko crumbs, then pan-fry for about 4 minutes on each side.)

Mushy mushy
While your catch is cooking, put the peas in a small heatproof bowl and pour boiling water over them. Leave to thaw for 5 minutes, then drain and add to a small blender. Add the remaining mayo ingredients and pulse to a chunky consistency; I still like to see a few peas. Taste for seasoning, adding salt and freshly cracked pepper to your liking, remembering that the fish fingies will be salted too.

Lettuce shred
Slice the lettuce into fine chiffonade ribbons, or tear into small flaps if that’s more your speed, then pop them into a salad spinner with cold water to get super crisp.

Slather up
Lay out your eight bread slices and generously butter each slice, right to the edges. Slather the mushy pea mayo onto four of the buttered bread slices.

Bring it home
Drain and spin-dry the shredded lettuce and place over the other four bread slices for your sarnie base. Top each with four fish fingers (or two crumbed fillets), the pickled ginger slices, a squeeze of lemon juice and a sprinkle of salt flakes. Place the bread lids on and press your sarnie together until you hear that satisfying crunch. Slice in half and serve with toasted seaweed snacks on the side.

Images and text from Weeknights with Alice by Alice Zaslavsky, photography by Rochelle Eagle. Murdoch Books RRP $45.00.

Hungry for more yummo recipes? Cook up a storm with Satoshi Narusawa's Japanese character bread buns or get your tastebuds dancing with Yotam Ottolenghi’s breakfast potatoes. To stay up to date on more rad recipes, sign up to our newsletter.