Pierce each potato with a fork six to eight times. In a microwave oven on high power, cook the potatoes until tender, 12 to 14 minutes, turning once. Carefully remove the potatoes from the microwave. When the potatoes are cool enough to handle, lay them on their sides and cut off the top third of each one. Using a spoon, scoop out the interior of each potato, leaving a shell about 8 millimetres thick. Put the potato pulp in a large bowl, add 1 tablespoon of the butter and gently mash together.
Cut the white and light green parts of the leeks into thin slices (you should have about 190 grams). Rinse well in a colander under cold water to remove any dirt. In a large saucepan over medium heat on the stove, melt the remaining 2 tablespoons of butter. Add the leeks and cook until tender and just beginning to brown, 8 to 10 minutes, stirring occasionally. Add the spinach, cover and cook until it wilts, 3 to 4 minutes, stirring occasionally. Remove from the heat and drain, if necessary.
Related Grill Skills
Add the spinach mixture and the cheese to the mashed potatoes and stir until well blended. Season with salt and pepper.
Prepare the grill for direct cooking over medium heat (180°C to 230°C).
Divide the filling evenly among the potato shells, piling the mixture high and stuffing them as much as possible.
In a small bowl toss the bread crumbs with the oil. Divide and press the bread crumbs into the top of each potato.
Brush the cooking grates clean. Grill the stuffed potatoes over direct medium heat, with the lid closed, until the potatoes are heated through and crusty on the top and bottom, 16 to 18 minutes. Using tongs, carefully remove the potatoes from the grill. Top with the chives and serve right away.
Brush the cooking grates clean. Grill the stuffed potatoes over medium heat, with the lid closed, until the potatoes are heated through and crusty on the top and bottom, 16 to 18 minutes. Using tongs, carefully remove the potatoes from the grill. Top with the chives and serve right away.