Deviled shrimp tostadas with avocado spread

Shallow-fry corn tortillas in avocado oil over medium heat, swirling and holding the centre down with tongs so they do not curl, a minute or two per side until blistered, golden and completely crisp.

Blot on a paper towel and cool on a rack. Salt the tortillas after frying.

Pour off all but about a tablespoon of oil and return the pan to medium-high heat.

Sear the shrimp about 30 seconds per side without cooking through.

Rest on a plate until cool enough to handle, about five minutes.

Pull off the tails. Split the thick end of each shrimp, then slice across into small uniform pieces and put in a bowl.

Squeeze in the limes; add ground chipotle, cumin, paprika, cayenne and a little salt, a drizzle of olive oil and a small spoon of ketchup. Mix well.

Cover with plastic and refrigerate at least an hour so the lime juice finishes 'cooking' the shrimp.

Halve and pit the avocado and scoop into a bowl. Add a big pinch of salt and the juice of one lime and mash as smooth or coarse as wanted (easier before the lime goes in).

Stir in finely diced jalapeno or serrano and chopped cilantro. Taste and adjust, press plastic on top and refrigerate.

Toss the shrimp with diced red onion, tomato, cucumber, chopped cilantro and a pinch of salt.

Spread a quarter of the avocado spread on each tortilla, not quite to the edges. Spoon over the shrimp and drizzle with Mexican crema.