Tuna Tostada

Ingredients

• ½ pound (227 g)sushi-grade ahi tuna, cut into 1.3 cm cubes
• 2½ tablespoons (37 ml)Kewpie mayonnaise
• ½ teaspoon (2.5 ml)fresh lime juice
• ¾ teaspoontogarashi
• ¾ teaspoon (3.75 ml)sesame oil
• 1 teaspoon (5 ml)soy sauce
• 1 tablespoonscallions, finely chopped
• 1 mediumripe avocado
• ¾ teaspoon (3.75 ml)fresh lime juice
• 1½ teaspoonsserrano pepper, finely chopped
• ¼ teaspoongarlic powder
• ¼ teaspoonkosher salt (Diamond Crystal)
• ¾ teaspoon (3.75 ml)sesame oil
• 6mini tostadas
• to tastetoasted sesame seeds
• to tastescallions, thinly sliced

Instructions

1. 1

   Mix the tuna sauce

   In a bowl, combine the mayonnaise, soy sauce, sesame oil, ½ teaspoon lime juice, finely chopped scallions and togarashi. Mix until the sauce is evenly combined.

2. 2

   Fold in tuna

   Add the cubed ahi tuna and fold it gently through the sauce. Cover the bowl and refrigerate until you are ready to serve.

3. 3

   Mash the avocado

   Mash the avocado in a small bowl to your preferred consistency. Add the remaining ¾ teaspoon lime juice, serrano, garlic powder, salt and sesame oil, then fold together.

4. 4

   Assemble tostadas

   Spread as much avocado mixture as you like over each mini tostada. Top with the tuna mixture, then garnish with thinly sliced scallions and toasted sesame seeds.

What are tuna tostadas?

Tostadas are crisp, flat shells commonly associated with Mexican cooking, topped with ingredients rather than folded like a taco. This version takes an American-style, seafood-forward approach, layering raw ahi tuna with avocado.

The contrast is what makes it work: crunchy shells, soft avocado and tender tuna dressed with a creamy, savoury, citrusy sauce. Togarashi and serrano bring heat, while sesame adds a nutty note.

Nutrition and macros by portion

The nutrition label shows one serving as written: 550 calories, 34g protein, 36g carbs, 32g fat.

The tuna supplies most of the protein, while the tostada shells contribute much of the carbohydrate. Mayonnaise, avocado and sesame oil account for much of the fat. Serve with a vegetable salad to add freshness and balance the meal.

Choosing the tuna

Sushi-grade ahi: use tuna specifically sold as suitable for eating raw, and keep it chilled until you are ready to prepare it. Cut it into evenly sized 1.3 cm cubes so the pieces are easy to eat and coat evenly.

Gentle mixing: fold the tuna into the sauce rather than stirring vigorously. This helps keep the cubes intact.

Getting the avocado texture right

Ripe avocado: it should give slightly when pressed, without feeling mushy. Mash it as smooth or as chunky as you prefer before folding in the lime, serrano, garlic powder, salt and sesame oil.

Taste the mixture before assembling. The lime lifts the richness, while the serrano supplies the fresh chilli heat.

Keeping the tostadas crisp

Assemble just before serving, since the avocado and tuna toppings soften the shells if they sit on them. Spread the avocado first to make a base, then add the tuna.

Use a light hand with the toppings so the mini tostadas remain easy to pick up and eat.

Balancing the flavours

Creamy sauce: Kewpie mayonnaise and sesame oil give the tuna its rich texture, while soy sauce seasons it with savoury depth. Lime juice keeps the dressing from tasting too heavy.

Heat and garnish: togarashi seasons the tuna, and finely chopped serrano gives the avocado a sharper chilli flavour. Finish with sesame seeds and sliced scallions for extra aroma and a little crunch.

Serving ideas

Serve the tostadas as soon as they are assembled, while the shells are crisp. For a more substantial meal, pair them with a simple salad or lightly dressed vegetables.

If serving as appetisers, arrange the toppings and shells separately until guests are ready to eat, then assemble in small batches.

Recipe notes & tips

• Keep the tuna refrigerated while preparing the avocado mixture.
• Cut the tuna into similar-sized cubes for an even coating of sauce.
• Use a ripe but still firm avocado so the topping is creamy rather than watery.
• Adjust the amount of serrano to suit your preferred level of heat.
• Toast sesame seeds gently until fragrant, taking care not to let them darken too much.
• Assemble the tostadas at the last moment to preserve their crunch.

Variations

• More citrus: Add a little extra lime juice to the avocado for a brighter finish.
• Milder heat: Reduce the serrano or leave it out of the avocado mixture.
• Extra crunch: Add finely diced cucumber just before serving.
• Herb finish: Scatter chopped coriander over the assembled tostadas.
• Larger shells: Use full-sized tostadas and divide the toppings between them.

Common mistakes to avoid

• Mixing the tuna too roughly: Fold it gently into the sauce so the cubes stay intact.
• Assembling too early: Add the toppings just before serving to keep the shells crisp.
• Using underripe avocado: Choose one that yields slightly when pressed for a smooth mash.
• Overloading the shells: Keep the toppings moderate so the mini tostadas are easy to handle.
• Leaving the tuna warm: Keep it chilled until you are ready to assemble and serve.

How to store

Store the tuna mixture and avocado mixture separately in covered containers in the refrigerator and use promptly; the avocado may darken over time. Keep tostada shells in a dry, airtight container, and assemble only what you plan to serve. Do not store assembled tostadas, as the shells will soften.

Frequently asked questions