If you’re vegetarian or not, TVP is your friend. TVP is short for ‘textured vegetable protein’. It’s a soy product that looks like bacon bits or small cat kibble. You can buy it in most grocery stores. I found it in my local bulk store. It’s cheap and good.
In case you get it without instructions, just add the same amount of boiling water to your amount of TVP and let it sit a couple minutes until the water is absorbed. That’s it cooked. For spaghetti sauce, just add the ‘cooked’ TVP to your tomato sauce and let it heat through. And you’re done.
You can use TVP pretty much anywhere you’d use ground beef. I’ve never tried making meatloaf out of it, but you might be able to. Just make sure you use enough of a binding agent, like egg or gluten, to keep it loaf-like. There’s no grease from TVP so you want to make sure it doesn’t just crumble. That’s why pasta sauces are so easy to make with it.
The tomato sauce pictured here is made from a half cup of TVP, half a jar of ready-made pasta sauce and about 2 cups of stewed fresh tomatoes. Add herbs as usual and that’s it. This has grated cheddar on top. You can also use parmesan of course.