Marinara Sauce

This is the marinara Sauce that I make for anything from polenta to pasta.  Definitely a go-to marinara sauce recipe.  Comes from Giada De Laurentiis - FoodNetwork
Ingredients:
1/2 cup extra-virgin olive oil
2 small onions, finely chopped
2 garlic cloves, finely chopped
2 stalks celery, finely chopped
2 carrots, peeled and finely chopped
1/2 teaspoon salt
1/2 teaspoon freshly ground black pepper
1 (32 oz.) cans crushed tomatoes
2 dried bay leaves
In a large casserole pot, heat the oil over a medium-high flame. Add the onions and garlic and saute' until the onions are translucent, about 10 min. Add the celery, carrots, and 1/2 teaspoon of each salt and pepper. Saute' until all the vegetables are soft, about 10 min. Add the tomatoes and bay leaves, and simmer uncovered over low heat until the sauce thickens, about 1 hour. Remove and discard the bay leaf. Season the sauce with more salt and pepper, to taste. ( The sauce can be made 1 day ahead. Cool, then cover and refrigerate. Rewarm over medium heat before using.) I makes more than we need for a meal so I divide it in 1/2 and freeze part of it. The night I want to use it, I take it out of the freezer to thaw. I sometimes put it in batches in the food processor to make the sauce smooth.