I was wrong about the eggs, but here's a list I found. Meat is the best source of iron as it's the most easily absorbed, but here are some other sources... Read the bit about vit c at the bottom too as Vit c helps the body absorb iron.
FISH
Tuna, salmon, mackerel, sardines, pilchards or kippers are all sources of iron.
BREAD & CEREALS
Iron fortified breakfast cereals are a popular choice with children (eg Weetabix, Rice Krispies, Shreddies). Wholemeal bread, brown pasta and brown rice all provide more iron than the white types.
DRIED FRUITS
Peaches and prunes are great sources. Dates, raisins and currants also contain some iron. Try these as snacks instead of sweets.
PULSES & LENTILS
Baked beans, kidney beans, lentils and soya beans are good sources of iron. If you eat curries, try giving him more dahl. Try lentil or bean soup.
GREEN VEGETABLES
Spinach, broccoli, spring greens, kale, okra, watercress and rocket all contain some iron.
Please note: cooking vegetables for too long destroys their vitamin C content, so try steaming or stir frying instead.
NUTS & SEEDS
Most nuts and peanut butter contain iron. Cashew nuts, sesame seeds and tahini are particularly good sources.
OTHER FOODS
Quorn and tofu are particularly good sources of iron for vegetarians. Bombay mix, plain chocolate, liquorice and treacle all contain iron - but should only be eaten in moderation, as they are high in fat and sugar.
Some foods help the body to use iron, while others slow down the rate at which your body absorbs it. So you should give your son a source of vitamin C with each meal e.g. fruit or diluted, unsweetened fruit juice to maximise the absorption of iron. All fruit, especially citrus fruits such as oranges, kiwi fruits and blackcurrants are great sources of iron. Fresh and frozen fruit are richer in vitamin C than tinned.