Adjust rack to middle position and preheat oven to 425 degrees. Wash and dry all produce. Halve poblanos lengthwise; remove stems and seeds. Drizzle each half with oil; season with salt and pepper. Place on a baking sheet and roast on middle rack until softened, 15-17 minutes.

Meanwhile, in a small pot, combine rice, 11/4 cups water (21/4 cups for 4), and a big pinch of salt. Bring to a boil; cover and reduce to a low simmer. Cook until tender, 15-18 minutes. While rice cooks, dice onion and tomato. Zest and quarter lime (for 4, zest 1 lime; quarter both). Mince chili. In a small bowl, combine sour cream, salt, pepper, and lime zest to taste. Add water 1 tsp at a time until mixture reaches a drizzling consistency.

Heat a large drizzle of olive oil in a large, preferably ovenproof, pan over medium-high heat. Add onion and cook, stirring occasionally, until slightly softened, 3-4 minutes. Add stock concentrate, Southwest Spice, half the tomato, and 2 TBSP water (1/4 cup for 4 servings); season with salt and pepper. Cook, stirring, until softened, 2-3 minutes. Turn off heat.

Stir cooked rice into pan with veggies until thoroughly combined. Return pan to medium-high heat. Stir in 1 TBSP butter (2 TBSP for 4 servings) until melted. Turn off heat. Season with salt and pepper.

Once poblanos are roasted, stuff each half with as much filling as will fit. Nestle into pan with remaining filling. (TIP: If your pan isn’t ovenproof, transfer remaining filling to a small baking dish and arrange stuffed poblanos in there.) Sprinkle poblano halves with Monterey Jack. Bake until cheese is melted and slightly crisp at edges, 7-8 minutes.

Meanwhile, toss remaining tomato in a second small bowl with a squeeze of lime juice. Season with salt and pepper. Divide filling and stuffed poblanos between plates. Top with guacamole, seasoned tomato, crema, and chili if desired. Serve with remaining lime wedges on the side.