Sweet Potato Tempura and Steak Sandwich with Bok Choy and Miso Mayo
Peer reviewed by UK recipe editorsAuthored by UK recipe editorsOriginally published 28 Jan 2026
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This steak and sweet potato tempura sandwich is a sophisticated, high-protein take on a classic fusion dish. By replacing traditional bread with crisp, golden planks of sweet potato tempura, you create a satisfying gluten-free base that pairs beautifully with the umami-rich components. The tender skirt steak, marinated in ginger and soy, provides a punchy, savoury depth that is lifted by the fresh crunch of charred bok choy and a luxurious miso-infused mayonnaise.
Perfect for a weekend lunch or an impressive midweek meal, this dish balances textures and temperatures for a truly professional finish. The use of a light tempura batter ensures the sweet potato stays light rather than heavy, while the hit of citrus in the mayo cuts through the richness of the beef. Serve it fresh from the pan to enjoy the contrast between the hot, crunchy tempura and the succulent, rested steak.
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Ingredients for Sweet Potato Tempura and Steak Sandwich with Bok Choy and Miso Mayo
2 teaspoons finely grated ginger
1 large clove garlic, finely grated
45ml vegetable oil, divided
2 tablespoons low-sodium soy sauce
1 tablespoon mirin
1/2 teaspoons kosher salt
1/4 teaspoons black pepper
275g skirt steak, cut into 2 pieces
2 heads baby bok choy, split in half lengthwise (230g )
1 large sweet potato
Vegetable oil, for frying
120ml plain flour
2 tablespoons cornflour
3/4 teaspoons kosher salt, divided
120ml very cold club soda
1/2 teaspoons white miso paste
60ml mayonnaise
1 teaspoon fresh lemon juice
A mandoline
How to make Sweet Potato Tempura and Steak Sandwich with Bok Choy and Miso Mayo
Back to contentsWhisk the ginger, garlic, 1 tablespoon oil, soy sauce, mirin, salt, and pepper in a small bowl. Place the skirt steak in a resealable plastic bag and pour the marinade over. Turn to coat and let sit at room temperature 30 minutes.
Remove the skirt steak from the marinade. Heat 1 tablespoon oil in a large skillet over medium-high heat. Add the steak and sear to desired doneness, about 3 minutes per side for medium rare. Let steak rest on a cutting board.
Wipe out skillet and heat remaining 1 tablespoon oil. Sear the bok choy cut side down over medium-high heat until browned, 2 to 3 minutes. Flip the bok choy over, add 60ml water, cover, and cook 2 minutes more. Remove bok choy and roughly chop.
Using a mandoline, carefully slice the sweet potato lengthwise into 1/8-inch-thick planks. Select 4 planks from the centre of the sweet potato that are similar in size. Meanwhile, fill a large Dutch oven or cast-iron skillet with oil to a depth of 1 1/2 inches and heat carefully to 177°C. Sift the flour, cornflour, and 1/2 teaspoons salt into a large bowl. Gently incorporate the club soda into the flour mixture; do not overmix. Coat 2 slices sweet potato in the batter and fry, turning occasionally, until golden brown, about 5 to 6 minutes. Repeat with remaining 2 slices sweet potato. Sprinkle with remaining 1/4 teaspoons salt and drain on a cooling rack placed over a sheet tray.
Assemble the sandwich: Mix together the miso, mayonnaise, and lemon juice in a small bowl. Thinly slice the skirt steak against the grain. Place 1 fried sweet potato slice on a plate and layer with half the bok choy, half the skirt steak and 1 tablespoon of miso mayo. Top with another sweet potato slice to form a sandwich. Repeat with remaining sweet potato slices to make a second sandwich.
The leftover miso mayo can be refrigerated for up to a week.
Disclaimer
While every effort has been made to ensure the information is accurate and up to date, individual needs may vary and dietary requirements can differ based on personal health conditions. Always check food labels and allergen information before preparing or consuming any recipe. If you have specific health concerns, allergies, intolerances, or are following a medically prescribed diet, seek advice from your GP, pharmacist, or a registered dietitian before making significant changes to your diet or lifestyle.
Article history
The information on this page is peer reviewed by qualified clinicians.
28 Jan 2026 | Originally published
Authored by:
UK recipe editors
Peer reviewed by
UK recipe editors

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