Roasted Tomato, Garlic & Onion Sauce

This recipe reproduces the rich, caramelized roasted tomato sauce shown in the image. Roasting the vegetables whole concentrates their natural sugars, creating a deep, velvety flavor profile perfect for pasta, pizza, or soup base.

Save

Prep & Cooking Overview

• Prep Time: 15 minutes
• Cook Time: 40–45 minutes
• Servings: 4 to 6

Ingredients

For Roasting:

• 3 lbs (approx. 1.3 kg) Roma or plum tomatoes, halved lengthwise
• 1 head garlic, peeled (whole cloves)
• 1 large yellow onion, cut into large wedges
• 3–4 tbsp extra virgin olive oil
• 1 tsp sea salt (or to taste)
• ½ tsp freshly cracked black pepper

To Finish/Blend:

• 1 handfull fresh basil leaves
• ½ tsp red pepper flakes (optional, for a subtle kick)
• 1 tbsp balsamic vinegar or a pinch of sugar (optional, to balance acidity if needed)

Instructions

Step 1: Prep the Tray

1. Pre-heat your oven to 400°F (200°C).
2. Line a large rimmed baking sheet with aluminum foil for easy cleanup.
3. Place the halved tomatoes, whole garlic cloves, and onion wedges across the sheet.
4. Drizzle generously with olive oil and season evenly with salt and black pepper. Toss gently to ensure everything is coated, then turn tomato halves cut-side up.

Step 2: Roast

1. Roast in the preheated oven for 40 to 45 minutes, or until the tomatoes are collapsed and lightly charred at the edges, and the garlic and onions are soft and golden brown.

Step 3: Blend

1. Remove from the oven and allow to cool slightly for 5 minutes.
2. Transfer all the roasted vegetables—including the pan juices—into a high-speed blender or food processor.
3. Add the fresh basil leaves (and red pepper flakes/balsamic if using).
4. Pulse until you reach your desired consistency (smooth or slightly rustic and textured).

Step 4: Serve or Store

1. Taste and adjust seasoning with extra salt, pepper, or herbs if necessary.
2. Serve hot over pasta, use as a pizza base, or thin with vegetable broth for a luscious roasted tomato soup.

Pro Tip: If storing, let the sauce cool completely before transferring to airtight jars. It will keep in the refrigerator for up to 5 days or in the freezer for up to 3 months.