Cut the baguette into 1 inch thick slices. And place them on a grill tray and grill them @ 200°C (400°F) until they turns into golden brown.
Heat a pan in medium flame and melt the butter. Once the butter is melted add onion, garlic and celery, mix all together and stir about 2 minutes.
After 2 minutes of cooking add chicken stock and let it boil.
When started to boil, add pea and cook for 2 more minutes.
After 2 minutes take the pan off the stove and let it cool down. Once it cool down, transfer them into a blender and blend it well.
Heat up the same pan at medium heat and pour the soup in. Add salt and pepper to taste.
Cut the roasted ham to a small slices and add them to the soup and mix well.
Transfer the soup into a soup bowl and sprinkle ham and chive over.