There’s nothing quite like homemade spaghetti sauce made from fresh garden tomatoes. This thick, roasted spaghetti-style sauce develops deep, rich flavor with very little hands-on time, making it perfect for summer harvests and stocking your pantry for the colder months. Whether you’re canning for later or making a small batch for dinner, this sauce is simple, flexible, and incredibly flavorful.
This homemade sauce is perfect tossed with a classic plate of my Keto Spaghetti for a simple, comforting dinner any night of the week, and it also works beautifully as a base red sauce for pizza, dipping, and other tomato-based dishes with simple seasoning adjustments.
This is the same versatile sauce I use throughout my kitchen whenever a red sauce is needed, from pasta nights to homemade pizza.
Ingredients
- 4 lbs fresh tomatoes, cored and cut in half
(I use garden tomatoes in the summer) - 1 onion, sliced
- 3 garlic cloves
- Italian seasoning, to taste
- ¼ cup olive oil
- 1 tsp salt
- 1 tsp sweetener (I use monk fruit)
- Dash of ground pepper
How to Peel Tomatoes (Highly Recommended)
Peeling your tomatoes before roasting makes a huge difference in the final texture of your sauce. Tomato skins don’t break down well and can leave unpleasant bits in an otherwise smooth sauce.
Blanching Method:
- Bring a large pot of water to a rolling boil.
- Score a small “X” on the bottom of each tomato.
- Boil tomatoes for 30–60 seconds, just until the skins start to split.
- Immediately transfer them to an ice bath for 1–2 minutes.
- Starting at the “X,” gently peel the skins off with your fingers.
Optional: After peeling, you can scoop out some of the seeds. This helps reduce bitterness and excess water, especially when using juicy garden tomatoes.
Once peeled (and seeded if desired), core the tomatoes and cut them in half.
Roasted Spaghetti Sauce Instructions
- Preheat oven to 375°F.
- Place tomatoes cut side down in a large roasting pan.
- Scatter sliced onion and garlic cloves around the tomatoes.
- Drizzle everything with olive oil.
- Roast uncovered for 1½ hours, allowing the tomatoes to soften and caramelize.
- Remove from oven and let cool slightly.
- Transfer everything to a food processor or blender.
- Add Italian seasoning, salt, sweetener, and pepper.
- Blend until smooth (or leave slightly chunky if preferred).
Taste and adjust seasoning as needed.
Yield & Batch Size
This recipe makes enough sauce for canning, but it’s easy to:
- Halve it
- Third it
- Or scale up for a large harvest
Perfect for preserving summer tomatoes without standing over the stove all day.
📖 Nutrition Information
Serving Size: ½ cup
Servings Per Recipe: 10
| Nutrient | Amount |
|---|---|
| Calories | 45 |
| Fat | 3 g |
| Protein | 1 g |
| Total Carbs | 6 g |
| Fiber | 2 g |
| Net Carbs | 4 g |
Disclaimer: Nutrition information is an estimate only and may vary based on brands used, portion sizes, and substitutions.
Canning Instructions (Water Bath)
If canning, make sure to follow safe canning practices.
- Fill clean jars with hot sauce.
- Leave 1 inch headspace.
- Wipe rims, apply lids and bands.
- Process in a water bath canner:
- Quarts: 45 minutes
- Pints: 40 minutes
- Remove jars and let cool completely.
- Check seals before storing.
Notes & Tips
- Roasting brings out natural sweetness and depth
- Removing skins and some seeds improves texture and flavor
- Monk fruit balances acidity without overpowering
- Blend smooth for spaghetti or leave chunky for lasagna and baked dishes
- Serve this sauce alongside my Keto Cheesy Bread or Keto Cheesy Biscuits for a low-carb, family-friendly meal that still feels cozy and indulgent.
This post may contain affiliate links. If you make a purchase through one of these links, I may earn a small commission at no extra cost to you.
Final Thoughts
This homemade roasted spaghetti sauce is a staple recipe when tomatoes are overflowing in the garden. It’s rich, simple, and perfect for preserving the taste of summer all year long. Once you try it this way, it’s hard to go back to store-bought.