Boil the pasta water: Fill a large pot with water and set it over high heat so it comes to a boil.

While the water heats, finely chop the shallot, slice the garlic, drain and slice the roasted red peppers, halve the olives, drain the tuna, chop the parsley, and zest and juice the lemon.

When the water is boiling, add 1 tablespoon kosher salt to the pot.

Add the spaghetti to the boiling water and stir for a few seconds so the strands do not stick together.

Cook the spaghetti until it is tender but still has a little bite in the center, 9 to 11 minutes depending on the brand.

Start the sauce: While the pasta cooks, pour the olive oil into a large skillet and warm it over medium heat.

Add the chopped shallot to the skillet and cook, stirring often, until it softens and looks glossy, about 2 to 3 minutes.

Add the sliced garlic to the skillet and cook for about 30 seconds, just until it smells fragrant. Do not let it turn dark brown.

Put the roasted red pepper strips and halved olives into the skillet. Cook them for 2 minutes, stirring a few times, until the peppers are hot and relaxed.

Add the drained tuna to the skillet. Use a spoon to break it into large flakes, and warm it gently for 1 minute.

Stir half of the lemon zest into the skillet so it perfumes the sauce.

When the spaghetti is almost done, scoop 1 cup of the pasta cooking water from the pot and set it aside.