To make your own tostada shells, heat 1/2 inch of safflower oil to 350 degrees in a straight-sided skillet. Fry corn tortillas, turning them every 30 seconds, until crisp and golden, about 2 minutes total. Drain on paper towels; sprinkle with coarse salt.



Ingredient Checklist


Instructions Checklist
  • Toss radishes with vinegar in a bowl. Season with salt; let stand.

  • Meanwhile, heat oil in a large straight-sided skillet over high. Add chiles and cook, stirring, 1 minute. Add onions and cook, stirring occasionally, until translucent, about 5 minutes. Stir in squash and season with salt and pepper. Cook, stirring, 1 minute. Stir in oregano.

  • Add 2/3 cup water. Cover, reduce heat to medium, and cook, stirring once or twice, until squash is tender and almost all liquid is absorbed, about 6 minutes.

  • Spread tostada shells with sour cream. Top with squash mixture and pickled radishes, dividing evenly. Drizzle with some of pickling liquid. Sprinkle with cheese and oregano leaves; serve.