In a food processor, finely chop the mushrooms and transfer to a bowl. In the food processor, puree the chicken breast and transfer to a separate bowl; refrigerate the chicken until ready to use.

In a large, shallow saucepan over medium heat, cook the mushrooms, stirring occasionally; they will begin to release their liquid and the mixture will become soupy. Continue to cook until all of the liquid has been reduced and mushrooms are fully cooked and gray in color. Transfer to a fine-mesh sieve and drain off any remaining moisture, then give them one last squeeze to make sure all of the liquid is removed. Transfer the mushrooms to a bowl and refrigerate until cold. 

In a large bowl, combine the chilled mushroom mixture, the chicken, cream, allspice, cinnamon, salt and pepper. Mix thoroughly until the ingredients are fully combined.

In a small bowl, stir together the flour and water until a loose paste forms.

On a clean, flat surface, place a spring roll wrapper with one corner facing you. Bush the 2 opposite sides of the wrapper with the flour mixture.

About one-third of the way up the wrapper from the point facing you, place 1/4 cup of the mushroom mixture and spread it out lengthwise. Bring the bottom corner to the top corner and gently seal the sides. Tightly roll the mushroom log, folding in the sides as you continue to roll. Repeat with the remaining wrappers and filling.

In a large stockpot, with enough room not to overflow, heat the oil to 350°F on a deep-frying thermometer. Carefully place the rolls in the oil and fry until golden brown and crispy. To be safe, use a probe thermometer to check that the internal temperature has reached at least 165°F.

Serve the rolls with the butternut squash ketchup (recipe below).

In a medium pot, combine the butternut squash, garlic, onion, brown sugar, vinegar, coriander, fennel, ginger, mustard and allspice. Add enough water to cover the ingredients and bring to a boil. Reduce the heat and simmer until the squash is soft, about 30 minutes. 

Transfer the squash mixture to a blender and puree until smooth. Return the puree to a clean pot and continue to reduce until the desired consistency is reached. Season with salt and refrigerate until ready to use.