Place tomatoes and chilies in a pan about 10 by 15 inches. Broil about 2 inches from heat, turning as needed, until vegetables are charred on all sides, 6 to 8 minutes.
Let stand until cool enough to touch.
Pull off and discard skin of tomatoes and chilies. Coarsely dice tomatoes.
Remove seeds from chilies for less heat. Finely chop chilies.
