Cooked something for the first time, a tomato soup. Dominant taste is flavorless water with a slight tinge. Where might I have gone wrong?

Was looking at this recipe https://www.instructables.com/Foods-of-Skyrim-Tomato-Soup/ 2 large Leeks (3 small) 1 TB Butter 2 cups Broth of Vegetables 1 pound Tomatoes (pureed) 1 TB Garlic 1/4 tsp from Salt Pile 1 tsp Basil 1 tsp Black Pepper I did not have leeks and the amount seemed like a lot so I used one small onion because I googled and it said it can be used as replacement for leeks. I also used a small can of tomato paste that was less than a pound. I did not have vegetable broth so I used water. I decided to add russet potato dices. I melted the butter, put in a squirt of olive oil and then sauteed the onion and potato for 15 minutes, adding the suggested seasoning, I only lightly sprinkled the salt though. Suddenly realized I hadn't put water in after 20 straight minutes of sauteeing, and my potatoes and onions had already turned brown. So I started hurriedly filling with water until it reached the brim of my multi cooker. My multi cooker has a capacity of 4 liters and is 1000 watts. I put in more water because I wanted more soup. I simmered it on low power for 20 minutes as suggested. Once it was done I realized it didn't taste good and told my dad. He said I might've underseasoned it and when he saw me lightly putting tiny bits of salt in my hand he gave me a tablespoon of it. It tasted slightly better but still not good. Later dad told me that you can use corn starch to thicken a soup, so I pulled it back out of the fridge. He put some corn starch in a measuring cup with water and mixed until smooth and then put it in my soup. This didn't seem to change much. He did say you would normally do it while cooking it though. Now I'm wondering if I put the water in too late and should've done it while sauteeing so the flavor would seep in or something submitted by /u/Carolina_Heart [link] [comments]