Chef John's Butternut Bisque Recipe

Ingredients

• 3 tablespoons butter
• 1 large onion, diced
• 1 teaspoon kosher salt, plus more to taste, divided
• 1 (2 pound) butternut squash
• 2 tablespoons tomato paste
• 1 quart chicken broth
• 1 pinch cayenne pepper
• 0.5 cup heavy cream or creme fraiche, plus more to garnish
• 2 tablespoons maple syrup, or to taste
• Chopped fresh chives for garnish
• Pomegranate seeds for garnish