Heat 2 teaspoons oil in a 12-inch skillet over medium-high heat. Cook zucchini with 1/4 teaspoon salt for 5 to 6 minutes, turning occasionally, until browned and barely tender; transfer to a bowl.
Add remaining oil, beef and onion to the skillet. Cook for 7 to 8 minutes, breaking beef into crumbles, until it reaches 160°F; spoon off excess fat.
Stir in garlic, tomato paste, cumin, ancho chile, oregano and remaining salt for 1 minute. Add broth and corn and simmer for 3 to 4 minutes until corn is hot and the sauce coats the beef.
Fold zucchini back in and warm for 1 minute. Scatter Pepper Jack over the skillet, cover and heat on low for 2 minutes until melted.
Remove from the heat, drizzle lime juice over the skillet and divide among 4 bowls.