Bell pepper curls (prepare first):

1. Halve each pepper and remove the seeds and ribs. Lay a half flat, inside up, and cut into julienne strips with a sharp knife. Place the strips in a bowl of ice water and refrigerate until they curl, at least 30 minutes.

Chili vinaigrette:

1. In a medium bowl, whisk together the chili garlic sauce, rice wine vinegar, and soy sauce. Gradually whisk in the canola oil until the vinaigrette has emulsified. Season with salt and white pepper. Taste and add more vinegar or oil to balance, if needed.

Tuna:

1. Working quickly on an impeccably clean cutting board, use a sharp thin-bladed knife to slice the tuna into 1/4-inch dice — slice, do not chop. Cover and refrigerate until ready to serve.
2. Just before serving, combine the diced tuna, scallions, and chili vinaigrette. Season with salt and white pepper. (Do not dress the tuna in advance — the acid will begin to cook the fish.)

Avocado:

1. Dice the avocados and toss gently with the lemon juice and a pinch of coarse salt. Set aside.

Plate assembly:

1. Using a mandoline or a very sharp knife, slice the cucumber into paper-thin rounds.
2. Place a ring mold in the center of a chilled dinner plate. Using the outside edge of the mold as a guide, arrange overlapping cucumber slices in a ring around the mold.
3. Spoon the tuna tartare into the mold and press down lightly. Top with the seasoned avocado.
4. Pile a small amount of dressed frisée in the center and garnish with a few bell pepper curls.
5. Carefully lift the ring mold straight up. Repeat with remaining ingredients. Serve immediately.