This is going to sound weird. But here goes…
My kids have been known to drink this tomato sauce from the bottom of the bowl— literally. I know —it sounds weird.
For me, a very large chunk of garlic bread to sop up the last spoonfuls of sauce at the bottom of the bowl and I’m good.
The cult obsession with this sauce comes from its simplicity thanks to the few number of ingredients (🍅 🧈 🧅) and minimal time it takes to make it. When a homemade tomato pasta sauce can be made in 45 minutes, hungry and busy pasta lovers pay attention.
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My favorite brands of tomatoes and butter
Here is the low-down on the brands of tomatoes and butter I prefer for this sweet tomato sauce recipe.
Canned tomato intel
There are a ton of canned tomatoes out there and my favorites are San Marzano canned tomatoes. I have a whole guide on how to buy San Marzano tomatoes and everything you ever wanted to quickly learn about exactly what you need to look to find authentic San Marzano tomatoes.
Because they’re not all the same and yes, I’m that obsessed.

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When it comes to canned tomatoes and most Italian ingredients, I recommend to always go for the best quality ingredients you can afford. And that doesn’t mean they’re going to be the most expensive.
Here are my top 3 favorites (look for the two D.O.P. certification seals on the side):
La Valle San Marzano D.O.P. Italian Peeled Tomatoes
Strianese San Marzano Tomatoes, D.O.P.
DeLallo Whole Peeled San Marzano Tomatoes, D.O.P.
Best brand of unsalted butter for tomato sauce
To this tomato sauce, the butter adds a silken texture and very subtle flavor and marries the tomato and onion to become even sweeter. It’s the secret ingredient.
My butter of choice for butter tomato sauce is:
Land O Lakes Unsalted Butter. Using only sweet cream, Land O Lakes is as pure and homemade as you can get.
I also love Kerrygold Irish butter which has a little higher percentage of fat. I haven’t used Trader Joe’s butter but I’ve read that it’s also very highly rated especially for baking.
Type of onion for tomato butter sauce

You probably know there are mainly four kinds of onions in the grocery store: yellow, white, red, and sweet. Five if you count green. (and I’m sure there’s lots more!) Each have their own place but some can also be swapped for one another.
Here’s a quick guide:
- White. The strongest of all with a thinner papery skin. and the most likely to produce tears. Good for when you want a distinct bite like in a raw salsa.
- Yellow. A little milder and slightly sweeter than white and the most all purpose onion. Get milder and sweeter the longer you cook them.
- Red. Very mild and also good in salsas or homemade guacamole.
- Sweet. Like the yellow, they are what they say. Sweeter with more of a Saturn-like shape.
In this easy tomato butter sauce, use the yellow but white or sweet works too!
How to make tomato sauce with butter and onion



Only 3 ingredients and 3 steps! Here’s what to do:
- If using canned tomatoes, puree them in a blender until they reach the consistency you want (I do 10 seconds or so).
- Add the tomatoes to medium saucepan along with one halved onion (skin removed and root trimmed) along with 5 Tablespoons of butter.
- Cook for 45 minutes and remove the onions using a slotted spoon or strainer.
Don’t pitch the onion!
Use it as a base for fried rice, to top homemade pizza or to mix in scrambled eggs.
Best uses for tomato butter and onion sauce
Layer in a meatball lasagna perfect for two.
Use instead of the meat sauce in cheesy homemade manicotti.
Some Sunday, make a batch of homemade gnocchi and ladle over this sauce.
As my grandmas said, “Mangia!”
Storage & Make Ahead:
Make ahead: Make this sauce a day or two ahead of when you plan to serve it. It’ll keep in the fridge for up to 4 days.
Freezing Tips: Allow the sauce to completely cool before storing in a freezer safe container or ziploc bag. Can freeze for up to 3 months. Defrost in the fridge or microwave before heating.

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Easy Tomato Sauce with Butter and Onion
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Ingredients
- 1 28 oz can whole, peeled Italian tomatoes, preferably San Marzano
- 1 yellow onion, cut in half from root to stem, ends trimmed
- 5 tbsp unsalted butter
- salt and pepper , to taste
Instructions
- In a blender or with a stick blender, blend tomatoes to desired consistency. I prefer my sauce smoother. You certainly can leave them whole and crush them right in the pan with the back of a wooden spoon.1 28 oz can whole, peeled Italian tomatoes
- Peel onion, cut in half, trim shaggy roots and add to the pan.1 yellow onion
- Add the butter a little salt and pepper (about 1 tsp of salt and maybe 1/2 tsp of pepper to start).5 tbsp unsalted butter, salt and pepper
- Simmer for 45 minutes uncovered until the fat starts to separate from the tomatoes.
- Adjust seasonings with salt and pepper.






Sounds yummy to my tummy, thank you so much
It is a winner for sure! 😊
I have been using this recipe for decades! I love it!
I always knew I liked you! 😊 It’s the absolute BEST!