Combine the oats, milk, pumpkin purée, brown sugar, cinnamon, nutmeg, and salt in a saucepan.
Bring the mixture to a gentle simmer over medium heat, stirring frequently as it starts to thicken and become fragrant.
Reduce the heat to low and continue cooking, stirring occasionally, until the oats are soft and the mixture is creamy, about 5-7 minutes.
Add the pumpkin chunks to the porridge and fold them gently into the mixture to warm and distribute evenly.
Cook for another 2-3 minutes until the pumpkin is heated through and the oats are tender.
Remove the saucepan from heat and let the oatmeal sit briefly to thicken further before serving.
Spoon the creamy pumpkin oatmeal into bowls and enjoy hot, topped with seeds or a drizzle of honey if desired.