1/2 cup finely shredded and chopped red or green cabbage
8 tsp crumbled queso fresco (or feta cheese)
To prepare salsa: Toast garlic cloves, jalapeño and onion in a dry medium skillet over medium heat, turning occasionally, until browned, fragrant and soft, 5 to 7 minutes.
Combine the tomatoes, garlic, jalapeño, onion and avocado in a blender or food processor. Process until smooth. Stir in cilantro, salt and pepper. Set aside for topping the tacos.
To prepare tacos: Preheat oven to 400°F.
Put squash in a medium bowl and add garlic, oil, 1/2 tsp oregano, 1/4 teaspoon salt and whole cumin seeds; toss to coat. Arrange on a baking sheet in a single layer. Bake until soft and beginning to brown, 20 to 25 minutes.
Meanwhile, combine beans in a small saucepan with the remaining 1/4 teaspoon oregano and 1/4 teaspoon salt, ground cumin, chili powder and pepper. Heat over medium-low heat for about 10 minutes.
Warm tortillas one at a time in a dry large cast-iron (or similar heavy) skillet over medium heat until soft and pliable. Wrap in a clean towel to keep warm as you go. Spoon 1/4 cup of the warm beans into each tortilla; divide the roasted squash evenly among the tacos and top each with cilantro, cabbage, 1/2 cup of the salsa and cheese. (Refrigerate the remaining 1/2 cup salsa for up to 2 days.)