Toast bread in butter in a hot pan over medium heat. Once bread is golden, transfer to a cutting board. Apply 1⁄4 cup avocado spread evenly to the toast. Next, mix crab with garlic aioli. Once thoroughly mixed, spread evenly atop avocado spread. Top with minced pickled red onion, serrano peppers and cherry tomatoes. Slice in two.

Mash whole avocado with the juice of one lime until smooth. Season with a pinch of salt.

Add all ingredients, except the oil, into a blender or a food processor. Turn on food processor and begin to slowly add in the oil. As the aioli begins to thicken, add a splash of ice water to thin it out ever so slightly. You want the aioli to be spreadable and not too thick. Taste for seasoning and add more salt and lemon juice if necessary.

Mix vinegar, water, sugar and salt in a pot and bring to a simmer, just to dissolve the salt and sugar. Cool immediately, and only use pickling solution cold. Once cold, submerge sliced red onions in pickling solution overnight.