1. Roast potatoes in a 350°F oven for 40-45 minutes. Cool slightly. Using hands, gently press down on potatoes to smash, but do not flatten completely.
2. Mix salt, dried oregano, and black pepper in a spice grinder. Process until fine. Add the remaining spices in the adobo spice recipe and put into a spice shaker.
3. Combine water, vinegar, sugar and 1/2 cup salt in a saucepan. Heat until sugar and salt are dissolved. Pour brine over chopped shallots and submerge until ready to use.
4, Peel and pit the avocados. Smash just enough that avocado chunks are visible. Gently fold in lime, queso fresco, shallot juice, cilantro, and salt. Marinate for 30 minutes.
5. Make a dressing by combining all Crab Louis ingredients except the crab. Toss the dressing into the crab meat making sure to keep chunks of crab intact. Marinate for 30 minutes.
6. Combine shredded cabbage and the chives in a bowl, set aside.
7. Fry potatoes in 350°F vegetable oil until golden brown and crispy. Toss in adobo seasoning shake.
8. Dollop avocado on top of each tostone. Top with crab salad and garnish with the shredded cabbage, serve 2-3 tostones per order.