Heat the olive oil (1/4 cup) in a large pot. Add the onion (1 cup) and saute, over medium-high heat, until soft, about 5-6 minutes. Add the grated carrot (1/4 cup), salt (1 1/2 teaspoons), and pepper (1 teaspoon) and saute until soft. Reduce the heat to low and add the garlic (4 cloves). Saute until fragrant, about 1 minute.
Add the rest of the ingredients. Simmer on low, uncovered, until the sauce thickens, about 1 hour. Thin the sauce if needed, by adding water.