Heat a large dutch oven or soup pot over medium-high heat. Add the olive oil. Once hot, add the onion. Cook until the onion is soft, fragrant and beginning to caramelize, about 10 minutes. Stir in the garlic, sage, rosemary and thyme. Season with salt and pepper, cook a minute longer or until fragrant.
Slowly pour in the chicken broth. Add the pumpkin, chicken and parmesan cheese rind. Cover the pot and simmer for 25-30 minutes or until the chicken is cooked through and shreds easily.
After 25 minutes, shred the chicken and remove any bones that may be in the chicken. Add the kale, lemon juice and lemon zest. Cook until the kale has wilted slightly, about 5-10 minutes. Taste and adjust the salt + pepper to your liking.
Bring a large pot of salted water to a boil. Boil the pasta according to package directions. Drain and toss the noodles with the butter and grated parmesan.
Meanwhile, make the toast. Preheat the oven to 350 degrees F.
Arrange the bread slices on a large baking sheet with sides. Spread each slice with butter and sprinkle with salt + pepper. Add the fontina evenly over each slice.
Transfer to the oven and bake for 10 minutes or until the cheese is melted and bubbling. Sprinkle with sage.
Remove the parmesan rind from the soup. Add the pasta to bowl and ladle the soup over the pasta. Top with fontina toast. Eat!