1) Break the garlic bulb open, place in a small roasting pan, and roast for 20 minutes, or until soft. Remove and when cool enough to handle, squeeze out the roasted garlic flesh.
2) Cook the sweet potatoes and carrots in a large pan of boiling water for 15 minutes, or until soft. Drain and mash then mix in the roasted garlic flesh.
3) Add the leeks, feta cheese, Tabasco sauce to taste, cilantro and pepper to the sweet potato mixture. Cover and let chill in the refrigerator for at least 30 minutes.
4) Preheat the oven to 375°F/190°C. Using slightly dampened hands, shape the sweet potato mixture into 8 small round patties and place on a non-stick baking sheet. Bake for 15 to 20 minutes, or until piping hot. Garnish with fresh herbs or salad and serve with tomato ketchup, if using. Divide the patties among 4 plates, 2 patties per person, to be sure of the portions.