Emeril's Queso

INGREDIENTS

• 1/2 pound fresh poblano or Anaheim chiles
• 2 tablespoons vegetable oil
• 1 cup chopped white onion
• 1/4 teaspoon cayenne pepper
• 2 tablespoons all-purpose flour
• 1 large tomato, peeled, seeded, and diced
• 1 cup milk, or cream
• 1 1/2 cups grated cheddar cheese
• 1 cup grated pepper jack cheese
• Coarse salt and freshly ground pepper