Cheesy Chile Strata

Name: Cheesy Chile Strata
Ingredients: 4 poblano chile peppers, halved lengthwise and seeded; 1 bunch medium spring onions, stems cut into 2-inch pieces, bulbs quartered; 1/4 cup masa harina (instant corn flour) or all-purpose flour; Vegetable oil, for frying (3 to 4 cups); 10 corn tortillas, cut into 2-inch pieces; 8 ounces Oaxaca or muenster cheese, grated (about 2 cups); 8 ounces pepper jack cheese, grated (about 2 cups); 8 large eggs; 3 cups whole milk; Kosher salt and freshly ground pepper; 1/2 teaspoon chili powder; Sour cream, chopped jalapenos and/or chopped cilantro, for topping (optional)