Preheat oven to 400 degrees.
Peel, seed, and cut butternut squash into 2 inch pieces. In mixing bowl, coat squash with 2 tbsps olive oil, 1 tbsp salt, and 1 tbsp of black pepper. Spread squash pieces on baking sheet and roast until to brown, approximately 30 minutes. While squash is browning, chop onion, mince garlic.
When the squash is brown, remove from oven, add the remaining oil to a large soup pot and saute the onion until just browning. Add the chicken broth, garlic, and browned squash, and bring to a boil, then reduce heat and simmer for 30 minutes.
Add cumin, 1 tbsp salt, 1 tbsp black pepper, 1/ tsp red pepper flakes. Using an emersion blender, blend soup until it has a smooth cream texture. Taste, and adjust seasonings to taste.
