Chicken Philly Sandwiches

INGREDIENTS

2 tbsp

olive oil, plus more for brushing the bread

1 lb

boneless skinless chicken breast, cut into bite-sized pieces

1/2 tsp

kosher salt

1/2 tsp

coarse ground black pepper

1/2 tsp

onion powder

1 tsp

dried oregano

large onion, thinly sliced

green bell pepper, thinly sliced

2 cloves

garlic, very finely minced

1/2 cup

water

8 oz

mushrooms, thinly sliced

1 tbsp

butter

1 tbsp

flour

1/2 cup

milk

6 oz

grated sharp white cheddar cheese

soft sandwich or hoagie rolls