Preheat oven to 400°F (200°C). Pierce eggplants all over with a fork. Wash bell peppers and place them whole on a parchment-lined baking sheet. Roast for 45-60 minutes, turning peppers occasionally, until eggplants are very soft and bell pepper skins are blackened and blistered.

Place bell peppers in a bowl and cover tightly with plastic wrap to steam for 15-20 minutes. Let eggplants cool slightly.

Peel the bell peppers (skins should come off easily after steaming). Remove seeds and stems. Cut eggplants in half and scoop out the flesh, discarding the skin. Roughly chop the peeled bell peppers and eggplant flesh.

In a large skillet or pot, heat olive oil over medium heat. Add chopped onion and cook until softened and translucent, about 5-7 minutes. Add minced garlic and cook for another minute, or until fragrant.

Add the chopped roasted bell peppers and eggplant flesh to the skillet with the sautéed onion and garlic. Stir well to combine. Stir in the red wine vinegar, tomato paste, smoked paprika, and cayenne pepper (if using). Season with salt and freshly ground black pepper to taste.

Bring the mixture to a simmer over medium-low heat. Reduce the heat to low, cover the skillet, and simmer for at least 30 minutes, or up to an hour, stirring occasionally. The longer it simmers, the more the flavors will meld and the spread will thicken. You want the mixture to be thick and jammy.

Taste the spread and adjust the seasoning as needed. You may need to add more salt, pepper, or a touch more red wine vinegar to balance the flavors.

For a smoother spread, use an immersion blender to puree the mixture directly in the skillet. Alternatively, you can transfer the mixture to a regular blender or food processor and blend until smooth. Be careful when blending hot liquids! If using a regular blender, let the mixture cool slightly first and vent the lid to prevent pressure buildup. I personally prefer a slightly chunkier texture, so I usually skip this step.

Stir in the chopped fresh parsley and basil (if using). These fresh herbs add a bright and vibrant flavor to the spread.

Let the spread cool completely before transferring it to an airtight container. Store in the refrigerator for up to a week. The flavors will actually develop even more as it sits!

Serve the eggplant and pepper spread at room temperature or slightly chilled. Drizzle with a little extra virgin olive oil before serving. It's delicious served with crusty bread, crackers, pita bread, or as a dip for vegetables. You can also use it as a spread for sandwiches or wraps, or as a topping for grilled meats or fish.