Preheat the oven to 425°F (220°C) until fully heated.
In a mixing bowl, toss diced potatoes, red bell pepper, and red onion with 1 tablespoon olive oil and half of the chili powder, smoked paprika, cumin, garlic powder, onion powder, kosher salt, and black pepper until well coated.
Spread the vegetables evenly on a baking sheet and roast for 20 minutes, stirring halfway through, until golden and tender.
While vegetables roast, whisk together eggs, milk, and a pinch of salt until combined.
Heat remaining 1 tablespoon olive oil in a nonstick skillet over medium heat. Add chopped green chiles and sauté for 2 minutes.
Pour in egg mixture and gently scramble until just set, then remove from heat to prevent overcooking.
Divide roasted vegetables evenly among four bowls. Top each with scrambled eggs, cherry tomatoes, avocado slices, shredded cheese, and a dollop of sour cream.
Garnish with chopped fresh cilantro and serve immediately, optionally with warm tortillas or tortilla chips.