A baby should get all the feeders it wants to eat 2 to 3 times day (3 times is better) in a 10 to 15 min timeframe each time.
There is no set amount on the greens/veggies, just make sure they are the best staple greens. If they eat them all up, refill the dish/bowl. Some babies don't show much interest in greens until several months old because their bodies are calling for LOTS of protein from feeders since they are growing at a fast rate.