To make the vinaigrette: Combine the cilantro, olive and canola oils, vinegar, garlic, sugar, and salt in a blender; puree until smooth. Taste and add more salt as needed.
To make the salad: Line a plate with paper towels.
Pour the peanut oil into a large skillet over medium heat. Once the oil is hot to shimmer, add 2 or 3 tortillas (or as many as will comfortably fit). Fry them on each side until crisp and golden brown, 1 to 2 minutes. Lift each tortilla with tongs and let the excess oil drip off, then transfer it to the paper-towel-lined plate. Working in batches, repeat with the remaining tortillas. Let the tortillas cool, then break them into bite-size pieces.
Toss the tortilla pieces with the lettuce, beans, scallions, feta, tomatoes, and ½ cup of the vinaigrette in a large serving bowl. Add the remaining ¼ cup of the vinaigrette, if desired, or reserve for another use. Serve immediately.
