1. Preheat oven to 425 F. On a large rimmed baking sheet add the butternut squash cubes, 3 tablespoons olive oil, 1 tablespoon salt, 2 teaspoons black pepper and 1 tablespoon chili powder. Toss to coat the squash. Bake for 30-40 minutes. Test doneness by piercing the squash with a fork. When it’s done, remove it from the oven and allow to cool for 5 minutes.
2. Meanwhile, in a medium sauce pan add the chicken stock and bring to a boil. Add the lentils and turn to medium-low and simmer for 15-20 minutes or until the lentils are tender but not mushy. Turn off the heat and allow them to cool for a few minutes.
3. Into a small mason jar, add the vinaigrette ingredients. Put the lid on the jar and shake vigorously to combine.
4. Into a large bowl add the red pepper, feta, spinach, parsley, pistachios, squash, lentils and vinaigrette. Toss to combine and serve immediately.