1. Place the white beans in a large pot of cold water. Bring to a boil. Remove from heat, cover, and let soak for at least 2 hours.
2. Drain the white beans. Wash the pot and put the white beans back in with 2 carrots cut into chunks, 2 chopped onions, and the bunch of herbs.
3. Cover with cold water, bring to a boil, cover the pot, and cook for 1 hour over medium heat.
4. Drain the beans, season with salt and pepper to taste.
5. In another pot, melt 100 g of butter and 2 tablespoons of oil. Add the remaining onions and cook for 2 minutes. Add the flour and mix with a wooden spoon. Add the wine and mix until smooth. Add 500 ml of water and combine.
6. Add the carrots cut into sticks, tomatoes, thyme, bay leaf, salt, and pepper. Simmer for about 20 minutes.
7. In a large skillet, heat the oil and 50 g of butter. Sear the lamb pieces. When browned, transfer to the sauce pot. Cook for 40 minutes over low heat.
8. Drain the lamb pieces and transfer to a large serving dish. Surround with white beans and red wine sauce.