Baked Ham & Swiss Pierogy Casserole - Mrs. T's Pierogies

Ingredients

• 1 1lb box of Mrs. T's Broccoli & Cheddar Pierogies
• 2 tbsp salted butter
• 2 tbsp flour
• 1 cup whole milk
• 1 1/4 cups Swiss cheese, shredded
• 1/4 tsp salt
• 1/4 tsp black pepper
• 1/4 tsp onion powder
• 1/2 cup cubed ham
• Olive oil