Preheat your oven to 400°F (200°C).

In a large mixing bowl, combine the cherry tomatoes, sugar, balsamic vinegar, olive oil, salt, and black pepper.

Transfer the tomato mixture onto a baking sheet and spread evenly. Nestle chopped red bell pepper and onion within the mixture.

Place whole garlic cloves in the center of the baking sheet and drizzle with olive oil, sprinkling with salt and pepper.

Roast in the oven for about 45 minutes until the tomatoes burst and caramelize.

Let the mixture cool for a few minutes, then squeeze the garlic pulp into a blender with the roasted vegetables.

Blend until smooth, adjusting thickness with water or olive oil as needed.

Transfer the sauce into jars or airtight containers for storage.