Adjust rack to middle position and preheat oven to 425 degrees. Wash and dry all produce. Dice potatoes into 1/2-inch pieces. Place in a medium pot with enough salted water to cover by 1 inch. Bring to a boil over medium-high heat and cook until tender, 15-18 minutes. Reserve 1/2 cup cooking water, then drain and return to pot. Cover.

Meanwhile, halve, peel, and thinly slice onion. Halve, deseed, and thinly slice poblano. In a medium bowl, combine panko, cheese, a drizzle of olive oil, 1 tsp Southwest Spice (we sent more), half the chili powder, salt, and pepper.

Lightly oil a baking sheet (or spray sheet with nonstick cooking spray). Pat chicken dry with paper towels; season with salt and pepper and place on prepared sheet. Evenly brush tops of chicken with half the sour cream (save the rest for later). Sprinkle panko mixture onto brushed sides, pressing to adhere.

Toss onion and poblano on other side of prepared sheet with a large drizzle of olive oil, salt, pepper, and remaining chili powder. Bake until chicken is browned and cooked through and veggies are tender and slightly crispy, about 15 minutes.

Using a potato masher or fork, mash potatoes until mostly smooth. Stir in remaining sour cream, 2 TBSP butter, and half the reserved cooking water. (TIP: If mixture is too thick, stir in remaining reserved water, a splash at a time, until creamy.) Season with salt and pepper.

Divide mashed potatoes and chicken between plates. Top with roasted veggies. Serve with hot sauce for drizzling over.