Cut the avocado lengthwise. Remove the pit and scoop out the flesh with a spoon. Grate the lemon and squeeze the juice. Finely chop the chives.

Place the avocado flesh in a blender. Add the lemon juice and zest, chives (reserve some for garnish), pistachios (reserve some for garnish), tomato, and flaxseed oil. Season with freshly ground black pepper, a pinch of cumin, and Himalayan salt. Blend until smooth.

Cover and refrigerate until ready to serve.

Cut the baguette into medium-thick slices. Spread the avocado and pistachio cream on the slices. Garnish with chives, some pistachios, and umeboshi paste.