J.P.
I make my own, and it's super easy but takes some time for chopping and cooking. I found that making a ton of it at once and freezing it is the easiest. I use ice cube trays for freezing, ziplocks for storing, and then I just defrost whatever I need for each meal. I agree that 4 months is early to start, so you can wait another month or two if you want. My son hated the rice cereal from the start, so we used oatmeal, but mainly as a filler with fruit. Sweet potato is easy- cook, add water, and mash with a fork (no blender for potatoes). Carrots- steam and blend with water. Banana and avocado don't need to be cooked, just mashed, other fruits need cooking and blending. I keep some jars for when we are out at mealtimes. I never added enough water so it was hard to blend. Eventually, I got it! Good luck!