In a large heavy-bottomed Dutch oven or stockpot, heat olive oil and butter over medium heat until melted and shimmering.

Add diced yellow onion and cook for 5 to 6 minutes, stirring occasionally, until soft, translucent, and sweet.

Stir in minced garlic, tomato paste, dried oregano, and smoked paprika. Cook for 2 minutes, stirring continuously, until tomato paste darkens to a deep brick red and releases an intense roasted aroma.

Add chopped roasted red bell peppers, hand-crushed San Marzano tomatoes with their juice, vegetable broth, salt, black pepper, and maple syrup (to balance acidity). Stir well to combine.

Bring soup to a lively boil over medium-high heat. Reduce heat to low, cover partially with lid, and simmer gently for 15 minutes to allow the sweet roasted peppers and rich tomatoes to meld together.

Remove pot from heat and add the packed fresh basil leaves directly into the hot broth.

Using a high-powered immersion hand blender, puree the soup on high speed for 2 minutes until completely smooth, silky, and uniform with zero lumps. (Alternatively, blend in batches in an upright countertop blender, venting lid with a kitchen towel).

Stir in the heavy whipping cream. Taste and adjust seasoning with additional sea salt or black pepper as desired. Warm over low heat for 2 minutes.

Ladle hot, velvety bisque into wide shallow bowls. Drizzle with a decorative swirl of heavy cream, shower with fresh basil chiffonade ribbons, and crown with crunchy garlic sourdough croutons. Serve alongside crispy grilled cheese!