1.Spray medium frying pan with cooking oil; heat on the stove over medium heat. Cook the sausages, turning occasionally with tongs, until they are browned all over and cooked through. Take the sausages out of the pan and put them on a chopping board; when cool enough to handle, slice the sausages thinly.
2.Boil or microwave the peas until tender. Pour the peas and the canned beans into a strainer over the sink; rinse under cold water then drain.
3.Cut the larger tomatoes in half; leave smaller ones whole. Tear larger basil leaves into smaller pieces.
4.To make the dressing, juice the lemon; put juice in a screw-top jar with the oil; tighten the lid then shake well. Season to taste with salt and pepper.
5.Put the sausages, peas, beans, tomato, basil and dressing in a large serving bowl. Crumble the cheese into the bowl; mix gently using two large spoons.