Start by trimming the ends off the zucchini and slicing each one in half lengthwise.
Use a paring knife to score the flesh of each zucchini half with small cuts.
Generously sprinkle salt on the zucchini to draw out moisture, then place them flesh-side down on a paper towel to drain for about 30 minutes.
Finely chop a shallot and mix it with salt and lemon juice, allowing it to steep to mellow the flavors.
Peel and dice a tomato, then let it sit to release moisture, straining off any excess liquid.
Drizzle the tomato mixture with olive oil and stir in finely chopped chives to create a relish.
After 30 minutes, pat the drained zucchini halves dry to remove any excess moisture.
Heat a carbon steel pan over high heat and add grapeseed oil.
Place the zucchini halves flesh-side down in the pan without adding more salt.
Cook for about three minutes, then flip the zucchini halves and cook briefly on the other side.
Transfer the pan to a preheated oven at 415°F and roast for 15 to 20 minutes until the zucchini is tender and lightly browned.
Once cooked, plate the zucchini and top it with the prepared tomato-shallot relish before serving.
