Combine yeast, milk, honey and flour; cover and let rest 30 minutes. Let rise twice.
Add remaining ingredients. Add more flour if Purée is not dry enough. Knead with dough hook until it forms a ball. Dough should not stick to sides of bowl. Cover, let rise two times.
Shape as desired. Brush with beaten egg and dust with sea salt. Bake at 400° F until deep golden brown.
Blend in a bowl together. Form into patties and broil in hot oven until juices run clear.
Sauté onions in butter on low heat until translucent. Add sugar and cook 5 minutes. Increase heat to medium. Add remaining ingredients and reduce to syrup consistency. Season with salt and pepper.
Assembly: Put the lamb 'slider? on the pumpkin brioche with the Sweet Onion Marmalade.
Makes: 4