01 - 
                Heat oven to 400°F. Butter 9x13 dish.
              
              
              
                02 - 
                Cook onions in butter, add garlic. Stir in flour until tan. Whisk in stock until thick, add cheese.
              
              
              
                03 - 
                Mix sauce with frozen hash browns, spread in dish.
              
              
              
                04 - 
                Cook 45 minutes, then broil 5 minutes for crispy top.
              
              
              
                05 - 
                Fry serrano slices in oil until brown. Drain and salt.