Prepare the chicken by combining the olive oil, balsamic vinegar, kosher salt, black pepper and minced garlic in a small bowl.
Add this mixture to a large plastic bag with the chicken breasts and place in the refrigerator for at least 5-10 minutes.
Remove the chicken from the refrigerator.
Take the chicken out of the marinade and place on a grill over medium heat for 10-12 minutes per side.
Prepare the butternut squash apple bruschetta by tossing the butternut squash and apples with the olive oil, minced garlic, kosher salt, black pepper, ground cinnamon, nutmeg, allspice, cloves and sage.
Place in an even layer on a baking sheet and into the oven for 15 minutes.
Once the chicken is grilled, slice each chicken breast and top with the butternut squash and apple bruschetta, then drizzle with the balsamic reduction.