Passata made from tomato paste is a perfect choice. Or are you trying to stay away from nightshades? In either case, there is no reason to worry about anything. Here are some of my favorite simple alternatives to tomato passata that can be made with or without tomatoes. What Is Tomato Passata? A sauce known as passata is prepared by peeling and de-seeding tomatoes before blending them together. that have been cooked for a short time and then pureed. In Italian cuisine, it is a common ingredient. The Best Tomato Passata Substitutes - Ingredients Based on Tomatoes 1. Canned Tomatoes 2. Diced Tomatoes 3. Fresh Tomatoes. The consistency of passata is very similar to that of canned tomatoes. However, the seeds have not been removed, and the tomatoes have not been pureed into a smooth consistency; rather, they remain in their whole or chopped form. One regular can of tomatoes, including the juice, is equivalent to approximately one-half regular jar of passata.
- Pasta Sauce / Marinara Sauce
The concentration of tomatoes in commercial tomato pasta sauces is slightly higher than that of passata. They can have additional flavorings added to them, like as onion or basil, which might be a nice thing or it might not. To achieve a consistency more akin to that of passata, you may either use an exact 1:1 substitution or thin the spaghetti sauce down with some water. When preparing a dish in which the sauce is going to be cooked anyway, you probably won't be able to tell the difference. 
- Tomato Paste
In its most basic form, tomato paste can be seen as tomato passata that has been subjected to a "triple" concentration process. Tomato paste has a flavor that is quite similar to that of fresh tomatoes, although it contains significantly less water. I frequently prepare my own passata by watering down tomato paste that has a concentrated flavor. To prepare passata, I mix together one part tomato paste with two parts water. Take, for instance: If you add 250 grams of tomato paste to 500 grams of water, you will get 750 grams of passata, which is approximately the same as a regular-sized jar of passata.
- Ketchup
In comparison to tomato passata, tomato ketchup has a substantially higher sugar content and a higher concentration of flavor. Make sure there are no other choices before settling on this one. To begin, half of the passata should be substituted with ketchup, and additional water should be added as needed. It is important to keep in mind that the flavor will wind up being noticeably sweeter. In addition to this, the spices and vinegar that are used to make ketchup will contribute additional flavors to the dish. Which can turn out to be a positive thing.
- Vine-Raw Tomatoes (Fresh)
The most watery and least concentrated form of tomato is a fresh tomato. They have seeds and skins within them. You may prepare a fresh passata by putting fresh tomatoes through your food processor and blending the resulting puree. Next, use a sieve to get rid of the seeds. You may peel the tomatoes first for an even more authentic look and feel. 
Tomato paste from passata
A tomato passata is a sauce that is produced from pureed tomatoes like paste that have been strained. It is a thin tomato sauce that is created exclusively from fresh tomatoes and serves as the foundation for a great deal of Italian cuisine. Because it is a straightforward and time-saving mixture to prepare and bottle, you will have the ability to savor the robust flavor of tomatoes throughout the entire year. Because the list of ingredients is so short, the challenge lies in locating the most flavorful tomatoes that have been allowed to ripen on the vine. If you already have some of those flourishing in your garden, then everything is in order. In any other case, explore the fruit and vegetable stores in your area for luscious tomatoes that have ripened on the vine. When they are let to ripen away from the vine, the flavor does not develop to the same degree. In its classic form, passata is prepared by passing raw tomatoes through sieve. In order to extract all of the tomato juice and pulp, the tomatoes are first ground up and then put through either a mill or a mouli. The tomato skins, which are ground up in a mill or a mouli, are the primary source of flavor and color in the finished product. After that, this raw tomato sauce is bottled up. On the other hand, tomato paste is produced from tomatoes that have been reduced to a thick and nutrient-dense paste by the cooking process. 
Now, a classic passata and this recipe for easy passata are not exactly the same thing. There are two reasons for this. To begin, because I am the one who is preparing it. Therefore, it is not fresh tomatoes that have been strained, nor is it tomatoes that have been boiled down to the consistency of tomato paste. It's a tomato sauce that's been simmered, and it works wonderfully as a foundation for both soups and pasta dishes. While the sauce is cooking, some of the water will evaporate. When it comes to the actual process of cooking with the passata, this reduces the amount of time needed for meal preparation and cooking. The second reason is that I don't remove the cores or seeds from the tomatoes before cooking them. I simply combine all of the ingredients. This approach is one of my favorites because it generates almost any waste and requires hardly any effort. Because I do not own a tomato passata machine, a grinder, or a mouli to use for this, I opt to use my blender instead. I have a blender that performs an excellent job of blending everything, including the seeds, and it's available to me at all times. Although there are sometimes complete seeds that are found, the vast majority of the seeds have been ground up. 
You can pass the tomatoes through a mill or a mouli multiple times to thoroughly extract all of the pulp and crush up the skins. If you don't have a mill or a mouli, you can use a food processor instead. Composting is an option for the leftover seeds and skin at the end of the process. Passata should always be cooked at some point in order to get the most out of its flavor. This is because passata is prepared from raw tomatoes. You have the option of bottling the raw passata and cooking it when you need it, or you may go ahead and prepare it right now. This is the method of making passata that I find to be the most successful. If it is not initially reduced by simmering, the consistency is quite watery. I split the passata among several saucepans, bring it to a simmer, and allow it to decrease by approximately one third, or until it is just slightly thicker. If you don't reduce it sufficiently, the sauce may still be pretty liquid, which indicates it will need additional cooking in the future. However, it will turn into a gorgeous deep red color and have a bit more texture. You can remove any foam that gathers on the surface by scooping it up. If you plan to consume this tomato passata recipe soon, you could store it in the refrigerator or freezer. However, if you want to store it for a longer period of time, you could bottle it and preserve it using the hot water bath method. This technique is appropriate for use with foods that are high in acid, such as citrus and stone fruits. Tomatoes just make the cut for inclusion here as well due to the fact that they also contain a good deal of acid. However, because it is not even close to the same quantity as citrus or stone fruit, a tiny bit of additional acidity should be added so that they can be properly bottled. Citrus and stone fruits have far higher acidity levels. Because the bottled product contains low acid concentrations, germs may be able to thrive there. Even while the risk isn't particularly high with tomatoes, it's always advisable to err on the side of caution. 
Before each jar is placed in the hot water bath, a small amount of citric acid can be added to each one of them. It only takes a quarter teaspoon per pint jar or 500 ml to get the job done. (The canning guidelines are available here. After it has cooled, pour the sauce into jars that have been thoroughly cleaned. You should leave a space of about 1.2 centimeters (1/2 inch) between the sauce and the top of the jar. After giving the rims a quick wipe down with a clean cloth, place the lids and/or preserving bands on the jars. Be careful not to screw them on too tightly.