Place ham in slow cooker.
Score top of ham to make cross-shaped slices.
Push 1 tsp cloves into top of ham.
In a medium sized saucepot, combine oranges slices, orange juice, sugar, ginger and mustard, and the other teaspoon of cloves.
Cook on medium for 5 minutes, until glaze has reduced in half.
Drizzle half of glaze mixture over ham, saving 1/2 the glaze to drizzle as it cooks.
Set slow cooker on high for 4 hours or low for 6-8 hours, and cover to cook.
Add more glaze every hour of cooking, and in the last hour, every 25 minutes.
When ham has developed a crunchy, dark brown glaze, remove from pan and serve immediately.
If you would like more crunch to your ham, you can place it under a broiler on high and let sugar crisp for 5-10 minutes (watch closely to make sure sugar doesn't burn.)