This is part of a series on ingredients to add to your homemade tomato sauce to give it a boost of flavor! For all the post in this series, click here to view them all.
Anyone that knows, knows I am a huge fan of the leek. I prefer them any day over onions. Leeks are more subtle. They add flavor without screaming from the mountaintops, "hey, there is leeks in this dish". Much less boisterous than the onion. And I can avoid that whole crying thing that onions cause, despite what methods I try to prevent it (my eyes just don't like onions). I like their fresh flavor as well. Also they make for excellent "onion rings" (check out my Food Network inspired recipe for them). When it comes to flavoring up my tomato sauce, you can bet that I am thinking leeks would make a great addition.
When you are shopping for leeks I have some tips for you. Leeks are available year round. The best leeks will be the ones you find at your local farmer's market during the late summer/early autumn. Plus the ones at the market I find to be cheaper. Often in stores they are by the pound and can end up being quite expensive, especially if you go the organic route. The size of the leeks matters for what you are going to use it for. I like the really big ones if I am making the leeks rings I mentioned above. Smaller ones are going for when I want to use them in multiple dishes. Pick out leeks that have the most white one the bottom. This is the most tender part of the vegetable. Don't throw those tops off, they are tough but we can use them as I will talk about in moment. Avoid leeks with brown spots on them or that feel soft, this is a sign of age.
What Parts to Use for the Sauce
When I make my tomato sauce, I use a food mill to filter out the skin and seeds. This way I don't have to worry about any peeling or seeds in my sauce and I can get a smooth product. This also gives me a great advantage. I can use the woody, green tops of the leeks to add flavor to the sauce and they will be filtered out by the food mill. If you don't filter them out they will be tough and hard to chew. I save the tender white parts of the leeks for other dishes where I want to bite into the leeks themselves. If you like a sauce with some chunks in it, then go ahead and use the white parts, that's totally fine.
In my experience the flavor of the tops aren't as strong, so I use alot of them - more than you might think. It depends on how much of the tops have been trimmed. Some stores will trim off a lot of the tops before selling. I last got my leeks at the farmer's market, so there was plenty green tops. You want a good handful. The top of 1 leek was good enough for me. I had a large stock put half full of Roma tomatoes ready to make sauce with. If you go with store bought leeks, I would suggest 2 or 3 leeks depending on how large they are.