In a heavy skillet, heat the vegetable oil and cook the chopped garlic until crisp-tender, about 2 minutes.
Add the chopped green chile and cook for an additional 1 minute.
Stir in the milk, cream cheese, salt, pepper, and flour.
Cook over medium heat, stirring frequently, until the cream cheese is melted and the sauce is blended.
Remove from heat and let the mixture cool for 10 minutes.
Fold in the frozen hash brown potatoes and frozen corn, mixing until well combined.
Transfer the mixture to a 2-quart slow cooker and top with grated Parmesan cheese.
Cover and cook on low for 7–8 hours, or until the casserole is set and the top is golden brown.
Serve immediately.
Notes / Tips / Wine Advice:
Serving Tip:Serve with a side of fresh fruit or a green salad for a complete meal.Wine Advice:Pair with a light white wine, such as Sauvignon Blanc, or a glass of sparkling water for a refreshing balance.