Bake the potatoes directly on the oven rack for 50 minutes, piercing with a fork halfway through. Remove from oven and let cool. TIP: To save time bake potatoes the night before and refrigerate until ready to use.
Whisk the eggs in a large bowl and add the tomatoes.
Cut the potatoes in half and lay cut side up on the baking sheet. Scoop about half of the potato from each piece and reserve for another use. Divide the egg mixture between the potatoes.
Sprinkle with cheese and bake for 15 minutes, until cheese is melted and eggs are set. Serve topped with the diced avocado on top. Garnish with cilantro if desired.