Black Bean Sandwich (Torta) with Blistered Jalapeños & Broccoli Slaw

Directions

1. Roast the onion and jalapeños: set the oven to broil and place a rack near the top. Slice the onion, spread it on a baking sheet, halve and seed the jalapeños, and add them to the sheet. Toss with a little oil and salt.
2. Broil until the vegetables are soft and charred in spots, flipping once for even browning, about 10 minutes. Keep the broiler on after removing them for later use.
3. Make the dressing and slaw: in a medium bowl, combine lime juice, yogurt, mayonnaise, maple syrup, salt, and pepper; whisk until smooth. Add grated carrot and broccoli slaw, then mix to coat.
4. Finish the slaw: strip cilantro leaves from stems, chop, and fold into the slaw. Set aside.
5. Prepare the bean mash: drain and rinse the black beans into another bowl. Add the spices, then crush with a fork or masher until mostly smooth with some texture.
6. Toast the buns and melt cheese: shred the cheddar. Transfer the broiled veggies to a small bowl. Split the buns and place them cut-side up on the sheet. Spread bean mash on the bottom halves, top with cheese, and broil briefly until the buns are lightly toasted and the cheese melts.
7. Build the sandwiches: slice the tomato, halve and pit the avocado, and scoop flesh out in slices. Layer tomato, avocado, onions, and the jalapeños on the bottom buns, then sandwich with the top halves. Serve with the broccoli slaw on the side.