Step 1

Preheat a grill to medium high. Put the eggs in a medium saucepan and cover with cold water. Bring to a boil, then remove from the heat and let sit, covered, 10 minutes. Drain and rinse under cold water until cool. Peel, chop and set aside.

Step 2

Meanwhile, drizzle the salmon with the juice of 1/2 lemon and season generously with salt and pepper; set aside 10 minutes.

Step 3

Make the dressing: Combine the juice of the remaining 1/2 lemon in a small bowl with the lemon zest, vinegar, shallot and tarragon; whisk to combine. Gradually whisk in the olive oil until combined; season with salt and pepper. Set aside.

Step 4

Brush the grill grates with vegetable oil. Lightly brush the lettuce, avocados and corn with vegetable oil. Grill the vegetables, turning, until well marked, about 2 minutes for the lettuce and avocados and 5 to 6 minutes for the corn; transfer to a cutting board. Meanwhile, grill the salmon, turning once, until just cooked through, 6 to 8 minutes. Transfer to the cutting board and let rest 5 minutes.

Step 5

Roughly chop the lettuce, discarding the core; transfer to a large platter. Add the basil and dill and toss. Cut the kernels off the corn and chop the avocado and salmon. Arrange the corn, tomatoes, hard-boiled eggs, salmon and avocados in rows over the salad; season with salt and pepper. Drizzle with the dressing and top with parsley.