Preheat the oven to 325°F.

Dust lamb shanks lightly with seasoned flour, shaking off excess.

Heat olive oil in a Dutch oven on high heat.

Cook shanks for 4-5 mins, turning, until browned on all sides.

Remove shanks from the pan and set aside.

Sauté chopped red onion in the same pan for 2-3 mins until tender.

Add chopped red pepper and crushed garlic and cook for 1 minute.

Return the browned lamb shanks to the pan.

Add chicken stock, red wine, cranberry sauce, dried cranberries, Dijon mustard, and rosemary to the pan.

Cover the Dutch oven.

Bake in the preheated oven for 2 1/2 hours, turning the shanks every 30 minutes, until the meat is very tender.

Stir in baby spinach leaves during the last 5 minutes of cooking.

Serve the lamb shanks on mashed potatoes, sprinkled with toasted sliced almonds.