To make the stuffing, preheat a non-stick pan over medium heat . Add 2 teaspoons of olive oil, a tablespoon of butter, the onion and garlic. Add the prosciutto and the pumpkin and season with salt and pepper. Turn off heat and allow the stuffing to cool. To create the cavity for the stuffing, use a long sharp knife (like a boning knife), and cut a 1-2 inch hole through the centre of the fillet, making a lengthwise slit. Turn the meat around and cut another slit in the same spot so that your knife completes the cavity. Insert a table spoon into the cavity to make sure the hole is even and goes all the way through. Pipe the filling into the cavity. Season the steaks with salt and pepper and sear in hot, pan for about 2 minutes on first side. Flip the steaks and sear for an additional 2 minutes then lower the heat to medium-high and cook until done (about 3-4 more minutes). In a separate pan, cook together chopped onions, garlic , rosemary and wild mushroom and reduce with Port .