Keep in mind chickens don't have hands or teeth so anything that isn't soft enough to bite chunks off of need to be cut up into bite size chunks. That would be quite small for 7 week olds. Things like broccoli, cabbage, radishes, etc. have to be chopped up or they'll ignore them.
Ridgerunner is right about the balanced diet. I understand wanting them to eat scraps and forage. It takes a very rare large pristine pasture in prime growing season to provide optimal nutrition for chickens. Nearly 100 years of exhaustive research has gone into poultry nutrition. I give grower feed free choice until they start laying and layer free choice after that. Mine do free range as soon as they want to venture outside but except for late spring and summer there isn't enough to sustain them. There's no protein in the field in winter.
Insufficient protein and they won't grow or lay well. Insufficient vitamins and minerals can cause a litany of problems like slipped tendon, roup, rickets, infectious anemia, fatty liver syndrome and prolapsed oviduct just to name a few.
Parasite load, infection and environmental stress like temperature extremes can make even the perfectly formulated rations insufficient.
Mine get all the scraps but with 40 to 80 birds, there's never enough to go around. I give a lot of meat and fish scraps too.
