Spicy Tuna and Avocado Tostadas
These Spicy Tuna and Avocado Tostadas bring restaurant-quality flavor to your table in under 30 minutes. Seared sushi-grade ahi tuna is layered over creamy avocado slices on a crispy tostada shell, then finished with quick-pickled red cabbage, fresh jalapeño, cilantro, and a drizzle of sriracha mayo. Bold, fresh, and satisfying — this is the weeknight dinner that looks and tastes like it took all day.
Equipment
- Cast iron skillet or heavy-bottomed pan Must get screaming hot for a proper sear
- Sharp knife For slicing tuna against the grain
- Cutting board
- Small mixing bowls Several needed for marinade, mayo, and cabbage
- Measuring spoons
- Tongs For flipping tuna steaks
Ingredients
For the Tuna and Tostadas
- 1 lb sushi-grade ahi tuna about 450g; must be labeled sushi-grade or sashimi-grade
- 4 tostada shells
- 2 tbsp sesame oil 30ml; use toasted sesame oil for best flavor
- 2 tbsp soy sauce 30ml
- 1 tbsp lime juice 15ml; freshly squeezed
- 1 tsp sriracha sauce 5ml; adjust to taste
- salt and black pepper to taste
For the Avocado Topping
- 2 ripe avocados sliced; should yield slightly to pressure but not be mushy
- 1 jalapeño thinly sliced; remove seeds for less heat
- 1/4 cup red cabbage about 20g, shredded
- 1/4 cup cilantro about 10g, chopped
- 2 tbsp rice vinegar 30ml
- 1 tbsp honey 15ml
- lime wedges for serving
For the Spicy Mayo
- 1/4 cup mayonnaise 60ml; Japanese Kewpie mayo recommended for best results
- 1 tbsp sriracha 15ml; adjust to preferred heat level
- 1 tsp lime juice 5ml; freshly squeezed
- salt pinch
Instructions
- Whisk together sesame oil, soy sauce, lime juice, and sriracha in a small bowl. Pat tuna steaks dry with paper towels, then coat in the marinade and let sit for 10 minutes at room temperature.
- Whisk together mayonnaise, sriracha, lime juice, and a pinch of salt until smooth. Adjust sriracha to taste, then refrigerate until ready to serve.
- Stir rice vinegar and honey together until the honey dissolves, then toss with shredded red cabbage and let sit while you cook the tuna. Drain excess liquid before assembling.
- Heat a cast iron skillet over high heat until smoking, about 3–4 minutes. Remove tuna from marinade, season with salt and pepper, and sear 1–2 minutes per side for rare or 3 minutes per side for medium-rare.
- Let tuna rest for 2 minutes, then slice against the grain into ¼-inch thick pieces using a sharp knife.
- Layer avocado slices on each tostada shell, top with sliced tuna, pickled cabbage, jalapeño, and cilantro, then drizzle with spicy mayo and a squeeze of fresh lime juice. Serve immediately.
Notes
- Use sushi-grade or sashimi-grade tuna if serving rare or medium-rare — it has been frozen to eliminate parasites and is safe to eat lightly cooked.
- Pat the tuna completely dry before searing; surface moisture prevents a proper golden crust from forming.
- Don't overcook the tuna — it goes from tender to dry very fast. Pull it off when the outside is golden and the center is still pink.
- Swap regular mayo for Japanese Kewpie mayo in the spicy sauce for a richer, tangier, restaurant-quality result.
- Assemble tostadas right before serving — the shells go soggy quickly once toppings are added.
- For a milder version, omit sriracha from the marinade, use less in the mayo, and skip jalapeño seeds.
- Make-ahead tip: The spicy mayo and pickled cabbage can be prepared up to 3 days ahead. Marinate the tuna no more than 2 hours before cooking.
- No tostada shells? Brush corn tortillas with oil and bake at 400°F (200°C) for 8–10 minutes until crispy.
- Store tuna, mayo, and pickled cabbage separately in the fridge. Tuna keeps for 2 days; mayo up to 5 days; pickled cabbage up to 1 week.
- Try diced mango, pickled red onions, microgreens, toasted sesame seeds, or crumbled queso fresco as extra toppings.
Nutrition
Serving: 1TostadaCalories: 385kcalCarbohydrates: 22gProtein: 28gFat: 21gSaturated Fat: 3gPolyunsaturated Fat: 5gMonounsaturated Fat: 11gCholesterol: 45mgSodium: 580mgPotassium: 720mgFiber: 7gSugar: 4gVitamin A: 12IUVitamin C: 25mgCalcium: 6mgIron: 10mg
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