Heat the oven to 425°F. Lightly oil a 2-quart baking dish, such as an 11x7-inch dish or a 9-inch square dish.

Put the thawed hash browns in a clean kitchen towel and squeeze out as much extra moisture as you can. This helps the potatoes brown instead of steam.

Transfer the hash browns to a large bowl.

Add 1 tablespoon of the olive oil, 1/2 teaspoon of the salt, and 1/4 teaspoon of the black pepper to the bowl. Toss until the potatoes are evenly coated.

Press the hash browns into the baking dish in an even layer, pressing some of the potatoes slightly up the sides to make a shallow crust.

Put the baking dish in the oven and bake for 15 minutes, until the edges look dry and lightly golden.

While the potato base bakes, heat the remaining 1 tablespoon olive oil in a large skillet over medium heat.

Add the chopped onion and poblano to the skillet. Sprinkle in a small pinch of the remaining salt and cook for 6 to 8 minutes, stirring often, until the vegetables are soft and the onion is lightly golden.

Add the ground cumin and the diced green chiles to the skillet. Stir for 1 minute, until the cumin smells warm and the chiles are sizzling.

Add the pinto beans to the skillet along with 1/4 cup water. Cook for 2 minutes, stirring gently, until the beans are hot.

Use the back of a spoon to lightly mash about one-third of the beans right in the skillet. The mixture should look a little creamy but still have plenty of whole beans.

Take the skillet off the heat. Stir in the sour cream, 1 cup of the cheddar, and half of the sliced scallions until the cheese starts to melt into the bean mixture.