In a 2- to 3-quart pan over medium heat, frequently stir onion and garlic in oil until vegetables are limp and beginning to brown, 5 to 8 minutes. Add rice and chilies; stir often until rice is opaque, 2 to 3 minutes.
Stir in broth, tomatoes (including juice), and 1/2 teaspoon salt. Bring to a boil over high heat, cover, reduce heat, and simmer until rice is tender to bite, 18 to 20 minutes.
Stir with a fork to distribute tomatoes evenly, and add more salt to taste. Mound rice on a platter.