Wash the pumpkin. Cut off the top about 1-2 inches from the stem. Scrape out all the seeds and stringy bits from the inside. Lightly grease the inside with oil and season with salt and pepper if desired.

In a medium saucepan, whisk together chicken broth, poultry seasoning, onion powder, garlic powder, black pepper, salt, parsley, and paprika. Bring to a simmer over medium heat.

In a separate bowl, whisk milk and flour until smooth. Gradually whisk this mixture into the simmering broth until the sauce thickens. Stir in cream cheese until melted and the sauce is creamy. Turn off heat.

Heat oil in a large skillet over medium heat. Add chopped onion and cook until softened (5-7 minutes). Add minced garlic and cook for 1 minute more.

Add diced carrots and broccoli florets to the skillet and cook for about 5 minutes until starting to soften. Stir in corn, cooked rice/quinoa, and cooked chicken.

Pour the creamy sauce over the mixture and stir to combine. Taste and adjust seasoning.

Spoon the casserole mixture into the prepared pumpkin cavity, leaving a little room at the top.

Place the filled pumpkin on a baking sheet. Cover loosely with aluminum foil and bake at 375°F (190°C) for 45-60 minutes, or until the pumpkin flesh is tender when pierced with a fork. Remove foil for the last 10-15 minutes to let the top brown.