crust

Spray three 12-cup mini muffin pans with nonstick spray. Preheat oven to 350°F. Combine masa, flour, and 3/4 teaspoon salt in processor; using on/off turns, process to blend. Add butter. Add shortening by rounded teaspoonfuls. Using on/off turns, process until mixture resembles coarse meal. Add 1/4 cup warm water and process just until moist clumps form, adding more water by teaspoonfuls if dry.

Transfer dough to work surface; form into ball. Roll scant tablespoonful dough between palms into 1-inch round. Flatten into disk, then press onto bottom and up sides of 1 muffin cup, keeping top edge of dough inside cup (do not form any overhang). Repeat with remaining dough.

Bake crusts until dry to touch and easy to remove from cups, about 35 minutes. Cool on rack. DO AHEAD Can be made 1 day ahead. Store at room temperature in airtight container.

filling and garnish

Heat oil in heavy medium nonstick skillet over medium-high heat. Add onion and sauté until soft, 2 to 3 minutes. Add chorizo and cook until browned and crumbly, breaking up sausage with wooden spoon or fork, about 5 minutes. Add 1/4 cup water and tomato paste. Stir until thickened, about 2 minutes. DO AHEAD Can be made 1 day ahead. Cover and chill. Rewarm filling before continuing.

Divide filling among crusts (about 1 teaspoon each). Spoon 1/2 teaspoon tomato salsa atop half of chalupas and 1/2 teaspoon salsa verde atop remaining chalupas. Garnish with avocado and cilantro leaves.