General cooking tips
Buy Seasonal Food : Food in season is the best you can buy. Apples taste better when they haven't been flown half way around the world. And buying in season encourages local producers who, boosted by factors like the rise in farmers' markets, are building a more sustainable food industry.
Buy Local Food : ...but at the same time, figure out what makes sense. It is more energy efficient to raise lambs in New Zealand and ship them to the UK than to raise them in the UK, because New Zealand lamb farming is more energy efficient. It is also more energy efficient to buy produce raised in Spain, than produce that has to be grown in greenhouses in the UK. Baby steps require figuring out which things make sense and which don't.
Kitchen Tip : Using a pressure cooker saves up to two-thirds of the cooking time, saves energy, and preserves the goodness in your food.