Step 1

In a food processor equipped with the S-blade, pulse the pecans, onion, chili powder, cumin, salt, coriander, and cayenne until the pecans are broken into pea-size pieces. Add the pinto beans and pulse a couple of times until they have broken down to roughly one-quarter of their original size.

Step 2

Heat the oil in a large sauté pan over medium heat. Add the pecan-pinto mixture and cook, stirring occasionally and breaking up the big chunks, until there is some browning on the crumbles, 3 to 5 minutes.

Step 3

To serve right away, divide the filling between the romaine lettuce leaves, them top each one with avocado, salsa, sour cream, if using, and cilantro. If prepping for later, store the lettuce leaves, filling, and toppings separately in the refrigerator for up to 7 days. Reheat the filling before serving, if desired.