Wash and dry all produce. Halve tomatoes. Trim and thinly slice scallions, separating whites from greens. Mince cilantro. Zest and quarter lime (for 4 servings, zest 1 lime and quarter both). Mince chili.

Melt 1 TBSP butter in a small pot over medium-high heat. Add half the scallion whites and 1/4 tsp turmeric (1/2 tsp for 4 servings; you’ll use more later); cook until fragrant, 1 minute. Stir in rice, stock concentrate, 3/4 cup water (11/2 cups for 4), and a big pinch of salt. Bring to a boil, then cover and reduce to a low simmer. Cook until rice is tender, 15-18 minutes. Keep covered off heat until ready to serve.

Meanwhile, in a medium bowl, combine tomatoes, cilantro, remaining scallion whites, and juice from half the lime (whole lime for 4 servings). Season with salt and pepper. If you like spicy food, stir in chili to taste.

In a small bowl, combine sour cream, a large squeeze of lime juice, and as much lime zest as you like. Stir in water 1 tsp at a time until mixture reaches a drizzling consistency. Season with salt and pepper.

In a second small bowl, combine cumin and 1/4 tsp turmeric (1/2 tsp for 4 servings; be sure to measure). Pat rockfish dry with paper towels. Season all over with salt, pepper, and spice mixture. Heat a large drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add rockfish and cook until opaque and cooked through, 3-5 minutes per side.

Fluff rice with a fork; stir in scallion greens and 1 TBSP butter (2 TBSP for 4 servings) and season with salt and pepper. Divide between plates. Top rice with rockfish; garnish with salsa fresca and crema. Serve with any remaining lime wedges on the side.