Preheat your broiler and bring a pot of salted water to a boil over high heat.
In a bowl, combine your panko, lemon zest, garlic powder, and olive oil and mix thoroughly, then put on your sheet tray and spread evenly. Put beneath the broiler on the top rack until golden brown, about 2 minutes. Watch closely so it doesn't burn! When finished, remove from the oven and set aside in a bowl.
Put the leeks onto the sheet tray and lightly brush with oil, then place under the broiler until the greens are starting to burn and the whites are soft, about 7-9 minutes. When cool enough to handle, cut the leeks into bite size chunks.
Drop the pasta into the boiling water and cook 12-13 minutes. When finished, drain the pasta, reserving a cup of pasta water, and put back in the pot with the leeks, lemon juice, and the can of tuna (including the olive oil). Stir all of this to combine and emulsify, using the extra pasta water to thin out the sauce until it is glossy and fully coats the noodles.
