In a large bowl, soak the beans overnight in plenty of cold water.
The next day, strain the beans and add them to a large pot. Cover with fresh cold water, add bouquet garni, halved onion, and carrot, and bring it to a simmer over medium heat.
Cover and simmer until beans are soft but not mushy, 45 minutes to 2 hours. Just before the end of cooking, add salt to taste.
Remove the bouquet garni and vegetables and discard them. Reserve the cooking liquid for later.
Meanwhile, in a wide saucepan over medium-low heat, warm the oil. Add the chopped onion and cook gently until soft but not colored, 6 to 7 minutes. Add the garlic and cook for 1 to 2 minutes more.
Stir in the tomatoes, cooked beans, and rosemary. Simmer for 10 to 15 minutes, adding some of the bean liquid if the stew is dry.
☞ TESTER TIP: Any cooked bean liquid that doesn’t get used in the stew can be frozen and used as a vegetable broth.
Season well with salt, black pepper, and sugar, to taste. The mixture should be loose and juicy but not swimming in liquid.
Notes
Leftover cooking liquid--Save any extra bean cooking liquid and use it as vegetable stock in this turmeric bean soup. The bean cooking liquid can be frozen for up to 4 months.
White bean gratin variation--Put mixture in a shallow ovenproof dish. Scatter a mixture of buttered crumbs and approximately 2 ounces (50g) grated Cheddar cheese (or a mixture of Cheddar and Parmesan or other well-flavored cheeses) over the top. Pop into a hot oven, or flash under a broiler, until crisp and golden on top.
Storage--Store leftover tomato and white bean stew in a sealed container in the refrigerator for up to 5 days or freeze for up to 3 months.
Dietary--This recipe is suitable for gluten-free, dairy-free, vegan, and vegetarian diets.