In a large skillet or Dutch oven, heat olive oil to medium heat. Add the carrots and onions and toss to coat with oil. Reduce heat to low, cover, and cook for 10-15 minutes, stirring occasionally, until veggies are softened.
Remove lid, add garlic, increase heat to medium high and cook until fragrant (about 1 minute). Add tomatoes, tomato paste, parsley, basil, red pepper flakes, one Tablespoon of sugar, and a generous sprinkle of salt and pepper.