Mix flour, chili powder, salt and pepper together. Roll shanks in this flour mixture. In a large Dutch oven, heat 2 tablespoons oil over medium-high heat. In batches, sear shanks on all sides to brown; remove from pan. Repeat process adding more oil as needed. Add onions, carrots, celery and garlic; sauté to brown. Add wine, stock, thyme, rosemary and bay leaves. Bring to a boil. Arrange shanks in two 13 by 9 by 2-inch baking pans, placing 4 shanks in each pan. Divide vegetable mixture in Dutch oven between baking pans, pouring over shanks. Cover with foil; bake at 325° for 2 1/2 hours, turning shanks half way through. The meat should be very tender but still on the bone. Remove shanks and keep warm. Strain sauce and reduce by half. Add butter; stir until melted. Serve 4 shanks with Three-Bean Ragout (see recipe below) and a little pan sauce. Pull lamb meat from remaining 4 shanks, reserve for sliders. Put all beans in a large pot, cover with cold water. Cover pot; soak beans for 6 hours or overnight. Drain beans and return to pot, adding bacon, thyme, oregano, stock, garlic and jalapenos. Cover with water. Bring to a boil for 2 hours, adding water as necessary. Season with salt and pepper.