Black bean and grilled butternut tostadas

Spread out the red onions, spray with oil and season with salt and pepper.

Peel the butternut neck with a knife rather than a peeler, which takes too much off, and cut it crosswise into slabs.

Grill the slabs oiled side down over the charcoal until brown and tender, about five minutes a side.

Warm the mashed black beans on the grill and chop the grilled vegetables.

Build each tostada: a smear of beans to hold the butternut and onions, then chipotle salsa and a little queso anejo.