Heat the oven to 400ºF.

• Peel and halve the red onion. Coarsely chop half for the black beans; thinly slice half for pickling.
• Trim the ends from the radishes. Cut them in half, then cut the halves into thin half-moons.

In a medium bowl, combine the sliced onion, radishes, and quick-pickle brine and toss to coat. Let stand, stirring occasionally, while you prepare the rest of the meal.

On a sheet pan, brush the tortillas all over with 2 tablespoons oil and season with salt; arrange side by side. On another sheet pan, drizzle the butternut squash with 1 to 2 tablespoons oil, season with salt and pepper, toss to coat, and spread in an even layer. Roast in the oven, rotating the pans halfway through, until the tortillas are crisp and the squash is tender, 12 to 15 minutes for the tortillas and 15 to 20 minutes for the squash. Transfer the tortillas to a plate while the squash finishes cooking.
While the tortillas and squash roast, prepare the eggs.

Bring a medium sauce pot of water to a boil, and fill a medium bowl with ice water. Carefully lower the eggs into the boiling water and cook for exactly 5 minutes for soft-cooked (for hard-cooked eggs, cook for 3 to 4 minutes longer). Transfer the eggs to the ice water to cool. Carefully peel the eggs.
While the eggs cook, prepare the black beans.

• Peel and thinly slice the shallots.
• Rinse the black beans.

In a large frying pan over medium-high heat, warm 2 tablespoons oil until hot but not smoking. Add the chopped onion and shallots, season with salt and pepper, and cook, stirring often, until lightly browned, 3 to 5 minutes. Stir in the black bean spice blend and cook until fragrant, about 30 seconds. Add the beans and cook, stirring occasionally, until warmed through, 2 to 3 minutes. Stir in the roasted squash and remove from the heat.
While the beans cook, prepare the garnishes.

• Cut the lime into wedges.
• Coarsely chop the cilantro.
• Cut the eggs lengthwise into quarters.

Set out the tortillas, black bean mixture, pickles, lime wedges, cilantro, eggs, and queso fresco. Invite everyone to assemble their own tostadas.

Chef’s tip If you prefer to crisp your tortillas in a large frying pan with a splash of oil over medium heat instead of roasting them in the oven, by all means, go for it.

Kids can!

• Oil the tortillas and butternut squash.
• Time and peel the eggs.
• Rinse the beans.
• Set out the tostada toppings.
• Help clean up.