Prepare the Miso Dressing: In a small bowl, combine olive oil, sesame oil, soy sauce, white miso, lemon juice, and brown sugar. Whisk until smooth and set aside.

Slice the Salmon: Thinly slice the sushi-grade salmon against the grain into bite-sized pieces. Arrange on a plate, covering to maintain freshness.

Prepare the Vegetables: Wash and thinly slice the cucumber and finely chop the red onion. Snip the chives into small pieces.

Assemble the Sashimi Bowl: Overlap salmon slices in a wide bowl, arrange cucumber, red onion, and chives over top, then sprinkle with sesame seeds.

Add the Finishing Touches: Drizzle the miso dressing over the bowl, season with flaky salt and black pepper, and add capers if desired. Serve with lemon wedges.

Optional Serving Variation: Cook sushi rice and add at the bottom of the bowl before layering toppings for a more filling meal.