Heat the olive oil in a large frying pan and add onion and garlic. Cook until onions are browned then add the Saclà cherry tomato & basil and the chargrilled peppers previously drained. Add the potatoes, and herbs and pour in the stock. Bring to the boil, then simmer for 20-25 mins. Add a little more stock if needed. Stir through the spinach or rocket and cook until wilted. Remove from heat, season to taste and serve with some warm crusty bread.