Dice tomatoes into small pieces. Put tomatoes, Rotel, and tomato sauce in a large pot, mix well and cook on medium to medium/high heat.
While tomatoes, Rotel, and tomato sauce cook chop onions, green pepper, and garlic. Once tomato mixture begins to lightly boil reduce to low heat and add onions, green pepper, and garlic.
Cook for 30 minutes. Finely chop all herbs and add to mixture. Bring to light boil for 5 minutes stirring constantly. Reduce heat. Add grated Parmesan, salt, and pepper. Cover and cook on low heat.
Cook sauce for several hours (I cook mine 3+ hours to get flavors out) stirring occasionally (stir frequently until mixture cools-especially on an electric stove that doesn't cool as quickly as gas)