How to create thick, hearty garlic marinara sauce? I've been searching online for a recipe for a robust garlic marinara sauce to no avail. Does anyone have any tips on how to make this kind of thick, hearty sauce from scratch?

This is what I've tried so far:

Tomato Paste (I don't have a blender)
1/2 teaspoon butter
1 cup diced onions
1/4 cup diced red chilies
1/4 cup whole milk cream
3 cloves of garlic
Fresh Basil


I fry the garlic and onions in olive oil and then add the tomato paste, chilies, basil and cream. It has not turned into the hearty kind of sauce one imagins on an Italian dinner table. Does anyone have any tips?
Ditch the cream and onions, and don't use tomato paste. Take a whole bulb of garlic, peel the cloves and leave them whole. 

Heat a cup of good olive oil over medium heat and add the garlic, stirring occasionally until very lightly brown and blistered: be careful not to burn it!

Then add 4 28oz cans of chopped/crushed Italian tomatoes and some chilli, being careful of bubbling oil, and simmer very gently for 4 hours. Season well.

This method produces a thick, intense sauce that you can use for pretty much anything. Keep in the fridge for a week or the freezer for months.