Salmon Pasta with Creamy Tomato Sauce

Steps

1. Bring the 4 liters of water to a boil in a large pot and add the coarse salt once it's boiling. Take the salmon out of the fridge, pat it thoroughly dry with paper towels, and season all sides with half the fine salt.
2. Halve half the cherry tomatoes and leave the rest whole. Thinly slice the garlic. Finely zest the lemon, then squeeze its juice. Snip the chives into 1/4 inch (5 mm) pieces.
3. Heat 1 tablespoon of the olive oil in a large skillet over medium-high heat until it shimmers. Lay the salmon in, rounded side down, and don't move it for 3 minutes: a golden crust forms and the flesh turns opaque a third of the way up. Flip it and cook for 1 to 2 minutes, to 122°F (50°C) inside: the center is still translucent. Set it aside on a plate.
4. Drop the penne into the boiling water and cook 1 minute less than the package directions.
5. In the same skillet, without washing it, lower the heat to medium and add the remaining 2 tablespoons of oil. Add the garlic and stir for 1 minute, until barely golden. Add all the tomatoes, the piment d'Espelette, and the rest of the fine salt, turn the heat to high, and cook for 6 to 7 minutes, shaking the pan, until the whole tomatoes burst and release their juices. Crush about half of them with a fork.
6. Lower the heat to low. Add the mascarpone, the lemon zest, and a ladle of pasta water, about 100 ml, and stir until the sauce is smooth, rosy, and barely simmering.
7. Scoop out another 150 ml of pasta water, then drain the penne. Add them to the skillet and toss for 1 to 2 minutes over medium heat, adding pasta water a little at a time, until the sauce is creamy and coats every piece.
8. Off the heat, break the salmon into large 1 1/2 inch (4 cm) flakes along its natural lines. Add them to the skillet with the juices from the plate and the lemon juice, then gently fold twice with a large spoon so they don't break apart. The heat of the pasta brings the salmon to 131 to 136°F (55 to 58°C): silky and pale pink in the center.
9. Serve right away on warm plates, sprinkled with chives and a grind of pepper.