No tomato, no cooking of the sauce at all. Everything except the pasta goes into the bowl raw and the hot pasta does the work.
Save a mugful of the pasta water before you drain. It is the only thing turning oil and lemon into a sauce that clings, and there is no second chance once it goes down the drain.
- Pasta on. Salt the water properly.
- In the serving bowl: drained tuna broken into flakes, chopped olives, capers, garlic granules, chilli, lemon juice, olive oil, a lot of black pepper.
- Drain the pasta, keeping the water. Tip it straight onto the tuna mixture and turn it over.
- Add pasta water a splash at a time, tossing, until it goes from oily to glossy. Usually two or three splashes.
The starch in that water is what emulsifies the oil and lemon. Without it you get pasta with oil on it, which is a different and worse dish.
Serves 2.