Heat the oven (with the oven rack in the middle) to 375°F.
For the croutons, in a medium bowl, toss the bread cubes with the oil and sprinkle with a little salt. Spread on rimmed sheet pan and bake for about 15 minutes, or until golden brown and crisp. Let cool.
For the vinaigrette, using a Microplane or fine grater, grate the garlic into a small bowl. Add the mustard, lemon juice, smoked paprika, salt, pepper, and oil and whisk together.
For the salad, tear the kale leaves (or chop the romaine) into bite-size pieces, rinse, and spin dry. Put into a large serving bowl. Cut the avocado into ½-inch pieces and add to the salad. Drizzle on the vinaigrette and toss well.
Divide among bowls and top with the croutons and Parmesan.
