In a large saucepan, heat olive oil and saute onions until they start to soften, about 3-4 minutes. Add garlic oregano, red pepper flakes and cook until garlic is fragrant, about 30 seconds. Add tomato paste and cook, stirring, 2 minutes. Stir in red wine and simmer to burn off the alcohol and until wine reduces by half, about 2-3 minutes. Add water and tomatoes, a pinch of sugar ,parmesan and basil leaves. Simmer on low heat for about 10-15 minutes to blend flavors and thicken sauce slightly. Take off heat and taste for salt and pepper.