Heat olive oil and butter in a large skillet or pot over medium heat.

Add the chopped onion and cook for 3-4 minutes until softened. Stir in the minced garlic and cook for another 1 minute until fragrant.

Add the arborio rice to the pot and stir to coat it in the butter and oil. Toast the rice for 2 minutes, stirring constantly.

Pour in the white wine and stir until it is mostly absorbed by the rice, about 1-2 minutes.

Begin adding the warm chicken stock 1/2 cup at a time, stirring frequently. Allow the rice to absorb the stock before adding the next 1/2 cup. Repeat this process for about 20 minutes or until the rice is cooked but still slightly al dente.

While the risotto is cooking, heat a small pan over medium heat and sauté the zucchini for 3-4 minutes until lightly browned. Set aside.

When the rice is nearly done, stir in the diced ham, sautéed zucchini, and pumpkin puree. Continue to cook for 2-3 minutes until heated through.

Remove the skillet from heat and stir in the grated Parmesan cheese and chopped parsley. Adjust seasoning with salt and black pepper to taste.

Serve immediately, garnished with additional Parmesan cheese and parsley if desired.