Bring a medium pot of salted water to a boil and cook the chickpea pasta according to package instructions until al dente.
While the pasta cooks, season the chicken breast with half of the sea salt and black pepper.
Heat olive oil in a large skillet over medium-high heat and sear the chicken until golden brown and cooked through, about 5-6 minutes per side.
Remove the chicken from the pan and set aside to rest, then slice into bite-sized pieces.
In the same skillet, add the minced garlic and chopped fresh sage, sautéing for 1 minute until fragrant.
Lower the heat and stir in the butternut squash puree and chicken broth, whisking until the sauce is smooth and heated through.
Add the cooked pasta and sliced chicken to the skillet, tossing well to coat every piece in the squash sauce.
In a separate small dry pan over medium heat, toast the walnuts for 2-3 minutes until they are fragrant and lightly browned.
Garnish the pasta with the toasted walnuts and the remaining sea salt and pepper before serving.