Cobblestone Chicken Pie

5 tbsp extra-virgin olive oil, divided
3 medium leeks, cut in half and sliced
2 c. sliced fresh mushrooms
1 c. sliced celery
1 c. chopped red bell pepper
1/3 c. flour
1/2 tsp dried rosemary
1/2 tsp kosher salt
1/2 tsp freshly ground black pepper
1 (14.5 oz) can reduced-sodium chicken broth
3/4 c. half-and-half
3 c. diced cooked chicken breast
1/2 c. frozen peas
2 tbsp dry white wine or chicken broth
2 c. 1/2-inch sourdough bread cubes
1/2 c. shredded Parmesan cheese

Heat 2 tablespoons olive oil in a large skillet over medium heat. Cook leeks, mushrooms, celery and red bell pepper until tender, about 15 minutes. Stir in flour, rosemary, salt and pepper and cook, stirring constantly, 1 minute. Stir in broth and half-and-half. Cook, stirring frequently, until thick and bubbly, about 5 minutes. Stir in chicken, peas and wine. Spoon into an ungreased 2-quart casserole dish. Toss bread cubes with Parmesan cheese and remaining 3 tablespoons olive oil. Sprinkle evenly on top of casserole. Bake for 30 minutes at 400 degrees, until casserole is bubbly around edges and bread cubes are golden. Serves 6.