Wash and dry all produce. Adjust rack to middle position and preheat oven to 425 degrees. Bring 3/4 cup water and 1 stock concentrate to a boil in a small pot. Halve poblanos lengthwise; remove cores. Rub with a drizzle of oil. Season with salt and pepper. Roast on a baking sheet until soft, about 20 minutes.

Once stock boils, add rice to pot. Cover, lower heat, and reduce to a gentle simmer. Cook until tender, about 15 minutes. Meanwhile, halve, peel, and dice onion. Finely chop jalapeño, removing ribs and seeds for less heat.

Heat a drizzle of oil in a large pan over medium heat. Add onion and jalapeño (to taste). Cook, tossing, until soft, 4-5 minutes. Add 2 tsp Southwest spice (we sent more) and beef, breaking up meat. Cook, tossing, until no longer pink, 4-5 minutes. Season with salt and pepper. Remove from heat.

In another small pot, stir together half the tomatoes (we sent more than needed), remaining stock concentrate, 1/3 cup water, remaining Southwest spice, and as much chipotle powder as you like (start with a pinch and add more from there). Season with salt and pepper. Place over medium-low heat and bring to a gentle simmer.

Once rice is done cooking, add to pan with filling. Toss to combine. Season with salt, pepper, and any remaining chipotle powder, if desired. (TIP: If your pan is not ovenproof, transfer mixture to a small baking dish at this point.) Stuff poblanos with as much filling as will fit. Place in same pan, nestling in remaining unused filling.

Drizzle sauce over stuffed poblanos. Sprinkle with cheese. Bake in oven until cheese melts, 2-3 minutes. Divide stuffed poblanos and filling from pan between plates and serve.