If using jarred roasted red peppers, skip to step 2. To roast your own, core the bell peppers and cut them into large pieces. Preheat the broiler in your oven and arrange the pepper pieces skin-side-up on a large baking sheet. Place under the broiler and roast, turning the baking sheet halfway, for 10-15 minutes, or until the peppers’ skin is black and blistered. Transfer the peppers carefully to a large bowl and cover with plastic wrap. Set aside for 15-20 minutes to steam and cool slightly. Once cool enough to handle, peel the skin off the peppers. Discard skin and set peppers aside.
Melt the butter in a large soup pot over medium heat. Add the onion and garlic and cook, stirring frequently, for 5-7 minutes, or until onion is soft and translucent. Add the smoked paprika, dried thyme, red pepper flakes, and a pinch of salt and pepper, and cook for an additional 30 seconds, or until fragrant.
Add the roasted red peppers and broth. Cover and simmer for 15-20 minutes.
Remove the pot from the heat. Add the cheese one handful at a time, stirring each handful through until completely melted. Stir in the heavy cream. Taste and season to your liking. Serve topped with extra cheese, chopped chives and croutons.
