Heat oil, three turns of the pan, in a Dutch oven over medium-high heat. Add potatoes and lightly brown. Add onions, celery and garlic; season with salt, pepper, spices and thyme, and stir to combine. Let soften 7-8 minutes then add stock, beans and tomatoes. Bring to a simmer and cook 45-60 minutes.
Serve stew in shallow bowls with grilled garlic Naan bread or toasted peasant bread slathered with garlic butter and sprinkled with parsley and salt.