Preheat oven to 400°F.
Put squash in a medium bowl and, using kitchen shears, finely snip chiles to taste into small pieces (seeds and all) into the bowl.
Add garlic, oil, 1/2 teaspoon 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.
Peel and finely chop the garlic when cool enough to handle; stir into the squash.
Meanwhile, combine beans in a small saucepan with the remaining 1/4 teaspoon oregano and 1/4 teaspoon salt, ground cumin, Mexican seasoning 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 Goose Poop and cheese.