Pour enough canola oil into a large deep pot to come 1 in. up side. Heat until it registers 350° on a deep-fry thermometer.
In a dry frying pan, toast ancho chile until fragrant; remove, then toast cumin and coriander seeds until fragrant and a shade darker, about 1 minute.
Snip chile into pieces with kitchen scissors or cut with a knife. Grind chile, toasted cumin and coriander, and 1 tsp. kosher salt in a clean coffee grinder; set aside.
Put flour in 1 bowl, eggs in a second, and panko in a third. In batches, dip shrimp first in flour, eggs, and finally panko to coat. Fry shrimp in hot oil until evenly golden, about 2 minutes.
Transfer with a slotted spoon to a rack set on a baking sheet. Liberally dust shrimp with ground seasonings.
Serve shrimp with tortillas, avocados, and slaw.
* Ancho chiles are the dried form of poblanos. Find at Latino markets and on the international aisle of well-stocked grocery stores. To make the slaw, mix an equal ratio of jicama matchsticks and thinly sliced green cabbage with chopped cilantro leaves; then season with lime juice and cilantro to taste.