Cook the orzo in a large saucepan of salted boiling water according to the packet instructions, then drain and return to the pan, but turn the heat off.
Drizzle generously with olive oil and add the garlic and tomato purée, then work into the orzo until evenly combined. Season well with salt and pepper and add the beans, chopped herbs and lemon juice and mix well.
Taste and adjust the seasoning if desired, then serve.