Chop veggies: Preheat oven to 425°F with a rack in the center. Peel and finely chop 1 teaspoon garlic. Peel and finely chop all of the onion. Coarsely chop tomato. Trim ends from green beans, then cut into 1-inch pieces.

Prep cod & broth: In a liquid measuring cup, combine clam broth concentrate, 1¼ cups water, and ¾ teaspoon salt. Pat cod dry, then season all over with 1 teaspoon each of the chorizo chili spice blend and salt. Drizzle each filet with oil, then rub seasoning into cod to make a paste.

Sauté aromatics: Heat 2 tablespoons oil in a medium ovenproof skillet over medium-high until shimmering. Add onions and garlic and season with salt. Cover and cook, stirring occasionally, until onions are softened and lightly browned, about 5 minutes.

Toast rice, add veggies: Add 1 tablespoon oil and rice to skillet with onions over medium-high heat. Cook, stirring, until well combined and some of the rice grains turn chalky white, 2–3 minutes. Stir in tomatoes and green beans.

Add cod & bake: Stir in clam broth and bring to a strong boil. Place cod in rice mixture and sprinkle with salt. Remove from heat, then cover tightly with foil or a lid. Bake on center oven rack until liquid is absorbed and rice is tender, 17–20 minutes (watch closely as ovens vary). Remove from oven and let rest 3 minutes.

Make herb salsa & serve: While cod bakes, trim scallions, then thinly slice. Coarsely chop cilantro leaves and stems, then combine with scallions and finely chop together. Transfer herbs to a bowl, then stir in 2 tablespoons oil and 1 teaspoon vinegar. Season to taste with salt and pepper. Serve cod and rice bake drizzled with herb salsa.