I don't think you should feel so guilty. My friend is a paediatric dietician and she says jars are fine and they are nutricious. She gives her DD a mixture of jars/home cooked food. Also, there are very strict controls over the ingredients that go into foods for under 3s. She does say that the downside of jars is the transition to family meals, but if you feed a mixture of jars and homecooked, it would be fine.
Some jars do taste manky and I agree with the poster who only gives her DC food she would eat. There are some jars that taste fine, though.
For the steak, once you've cooked it, cut it up quite small, put some veg with it, pour full fat cow's milk on and blend it with a hand blender. Depending on how many teeth she has, it is fine to blend meat at this age IMO. If you get a hand blender that has a diswashable detachable end, then this cuts down the hassle. Mine was around £14.
You can also get (from some Asdas and Sainsburys) Babylicious and Kiddylicious meals. These are cooked from fresh, good quality ingredients and snap frozen. See link:
www.babylicious.co.uk/Home/tabid/131/Default.aspx
Also, if you consider a homecooked meal that an adult might eat, it may not be all that "homecooked". eg what if there is a jar (like ragu or something) of red sauce on the meal? If you get some chicken breasts from the supermarket - they must have been preserved in some way to give them a sell by date of a few days because fresh chicken does not keep that long. Do not feel so guilty