Preheat the oven to 425°F. Line a baking sheet with foil and lightly coat with non-stick spray. Cut the bell pepper in half and remove the seeds. Place cut side down on the baking sheet. Peel the onion and cut into wedges and trim the root end of each garlic clove. Trim the stalk but otherwise leave the Fresno peppers whole. To make a milder sauce, remove the seeds and membrane from the Fresno peppers. Arrange the vegetables on the baking sheet.
Lightly drizzle the vegetables with olive oil and season with kosher salt. Roast for 35 to 40 minutes until the peppers and onions are charred and very soft.
After roasting, cover the pan with foil and let the vegetables cool for 10 to 15 minutes. Remove the skin from the bell pepper if desired. Transfer the bell pepper, whole Fresno peppers, and onions to a high speed blender or food processor. Squeeze the garlic from the skins into the blender.
Add the apple cider vinegar, water, molasses, Worcestershire sauce, smoked paprika, kosher salt, and pepper. Blend until the sauce is smooth.
This roasted pepper sauce can be stored in the fridge for 2 to 3 weeks or it can be frozen for longer storage. Serve this fiery pepper sauce whenever you want to add a touch of smoky heat to your meal. It is particularly delicious served alongside grilled meats and vegetables. Enjoy!
Notes
To make this sauce milder, remove the seeds and inner membrane from the Fresno peppers before roasting.While you can easily remove the skin from the roasted bell peppers, it can be difficult to remove from the Fresno peppers after roasting. I recommend leaving the skins on the Fresno peppers and blending them whole.If you can't source Fresno peppers, red or green jalapeño peppers make a great substitute.