If the potatoes are big, cut them into bite-sized pieces. Rinse, then put them into a pan of cold water.
Bring to the boil and simmer for 15 minutes, then add the beans, bring the to the boil again and cook for 2-3 minutes. Drain, and keep warm or put aside.
When you’re ready to serve, cut the onion into thin slices and mince the garlic.
Heat some oil in a frying pan and add the onion and gently sauté it. Add the garlic, tomatoes and spices. Cook for a minute, then add the potatoes and beans. Season with salt and pepper. Put a lid on and let it steam for a couple of minutes. Add the lemon juice and a drop of water it the tomatoes haven’t released enough jus. Cook for another 3 minutes or so.
Stir in the fresh herbs and serve.