Green Chile con Queso

Name: Green Chile con Queso
Ingredients: 3 large poblano peppers, halved and seeded; 2 Tablespoons olive oil; 1/2 medium-sized onion, diced (about ¾ cup); 2 large jalapeños, seeded and minced (about 1/3 cup); 1 medium-sized tomato, diced (about 1 cup); 2 Tablespoons all-purpose flour; 1 1/2 Cup milk; 1/2 Cup (2 ounces) shredded Monterey Jack cheese; 3/4 Cups (3 ounces) shredded Oaxaca (white Mexican cheese) or additional Monterey Jack; 1/2 Cup (2 ounces) shredded white Cheddar; 1/2 Cup sliced scallions; 1/2 Teaspoon kosher salt; Tortilla chips, for serving