Rinse and drain 15 oz. chickpeas in a colander. Measure out ½ cup; reserve remaining chickpeas for another use.

Finely grate zest of 1 lime with a microplane or grater into a small bowl.

Cut lime in half and squeeze juice from one half into bowl with zest. Cut remaining half into 2 wedges; set aside for serving.

Gather 8 cilantro sprigs on cutting board. Starting at the stem end, finely chop stems until you get to the leaves; reserve leaves for serving. Add stems to bowl with lime.

Add ¼ cup yogurt and ½ tsp. salt to bowl and mix with a spoon to combine.

Remove casing from 2 chorizo links; discard. Heat a medium nonstick skillet over medium-low. Cook chorizo, breaking it up with a wooden spoon, until partially cooked, about 3 minutes.

Add reserved chickpeas and remaining ½ tsp. salt and mash together with back of spoon until chorizo is cooked through and crispy, 7–10 minutes. Remove from heat.

Spread reserved crema over 4 tostada shells.

Top crema with chorizo mixture.

Top with reserved cilantro leaves and serve with reserved lime wedges alongside.