3 tablespoons vegetable oil, plus more for frying
2 1/2 teaspoons chili powder
1 teaspoon chipotle chile powder
Kosher salt and freshly ground pepper
1 pint cherry tomatoes, halved
1 large red onion, cut into 1/2-inch wedges
1/2 spaghetti squash, halved and seeded
1 15-ounce can black beans (do not drain)
8 corn tortillas
1/2 cup sour cream
Fresh cilantro, for topping
Lime wedges, for serving