Preheat oven to 425 degrees and line a large baking sheet with parchment paper.
On the baking sheet, toss the butternut squash cubes and smashed garlic with 1 tablespoon of olive oil, oregano, rosemary, sage, and a pinch of salt and pepper. Roast for 25 minutes. Let cool, then blitz in a food processor until creamy and smooth. If needed, add 1-2 tablespoons of vodka to thin. This will yield about 1 cup of puree.
Boil a large pot of salted water. Cook the shells according to package directions. Drain.
In a large skillet, heat 1 tablespoon olive oil over medium heat. Saute the shallots for 4-5 minutes until fragrant. Stir in the red pepper flakes, then tomato paste and the butternut squash puree. Pour in the vodka and simmer until most of the liquid cooks about, about 5 minutes. Whisk in the butter and coconut milk. Simmer gently, stirring occasionally, for about 10 minutes. If needed, transfer the sauce to a deep-sided, oven safe baking dish.
To make the cheese filling, fold the ricotta with the fontina, parmesan, and kale.
Assemble the shells. Add about 2 tsp cheese filling to each pasta shell and nestle in the butternut vodka sauce. Repeat until all shells and filling are used up. Spread the torn mozzarella cheese over the shells. Bake for 20-25 minutes until the cheese melts and starts to turn golden in places. Garnish with fresh basil or rosemary.