- Preheat broiler. Spray baking sheet with nonstick spray.
- Place bell peppers on prepared baking sheet and broil 5 inches from heat, turning occasionally, until lightly charred on all sides, about 5 minutes. Place peppers in large bowl, cover with plastic wrap, and let stand until cool enough to handle. Peel peppers, discard seeds, and coarsely chop.
- Meanwhile, heat oil in small nonstick skillet over medium heat. Add onion and cook, stirring occasionally, until tender, about 10 minutes. Add garlic and thyme and cook, stirring constantly, until fragrant, about 30 seconds.
- Combine bell peppers, onion mixture, lemon juice, vinegar, salt, and cayenne in food processor and pulse until almost smooth. Serve immediately or transfer to covered container and refrigerate up to2 days.
- Per serving: 1/4 cup
You can make this dip with yellow or orange bell peppers instead of red, if you prefer.