Snow-Day Tomato Soup

Ingredients

• 1 28-oz can whole peeled tomatoes (preferably San Marzano)
• 8 garlic cloves, smashed and peeled
• ¼ cup Sizzle Kosher Salt
• Big Pinch of Granulated Sugar
• 2 tbsp unsalted butter
• 1 large yellow onion, thinly sliced
• 1 tsp fennel seeds
• ¼ tsp crushed red pepper flakes
• 3½ cups low-sodium chicken or vegetable stock or water
• Crème fraîche, sour cream, or whole milk yogurt (for serving)
• Drizzle (for serving)
• Small handful of fresh basil leaves (optional; for serving)