Pour the hot brine over the sliced onions, pressing to submerge. Let cool to room temperature, then cover and refrigerate for at least 30 minutes (best if 1 hour) before using.

Butternut squash

Peel the butternut squash, cut off the ends, halve lengthwise, scoop out seeds, and cut into 1/2-inch thick half-moon slices or 1/2-inch cubes for tacos.

In a large bowl, toss the squash pieces with olive oil, ground cumin, smoked paprika, kosher salt, and black pepper until evenly coated.

Heat a large skillet over medium-high heat and add vegetable oil for shallow frying. When oil shimmers, add squash in a single layer (work in batches if needed). Fry until golden brown and just tender, about 3–4 minutes per side for slices or 4–5 minutes total for cubes, turning occasionally so pieces brown evenly.

Transfer fried squash to a paper towel–lined plate to drain and lightly season with a pinch of salt while hot.

Chipotle slaw

In a medium bowl combine mayonnaise, Greek yogurt, lime juice, chipotle in adobo (finely chopped or blended to make 1 tsp paste), honey, salt, and black pepper. Whisk until smooth.

Add shredded green cabbage, red cabbage, and grated carrot to the dressing. Toss thoroughly to coat. Taste and adjust seasoning with extra salt or lime if needed. Refrigerate until ready to assemble (can be made up to 4 hours ahead).

Warm tortillas and assemble

Warm the corn tortillas: heat a dry skillet over medium-high heat and warm tortillas 30–45 seconds per side until pliable, or wrap in foil and heat in a 300°F (150°C) oven for 8–10 minutes.

To assemble each taco: place 1 tortilla on a plate, add 2–3 pieces of fried butternut squash, top with 2–3 tablespoons of chipotle slaw, a few pickled red onion slices, a sprinkle (about 1–2 tablespoons) of crumbled queso fresco, and a little chopped cilantro.

Serve immediately with lime wedges for squeezing over the tacos.