Shrimp Tostadas with Sweet Potatoes

1 pound sweet potatoes, peeled and cut into 1/2-inch cubes
12 cups shredded lettuce
6 tortillas, crisped hard and flat just before serving
2 small cucumbers, peeled and cut into matchstick strips
1 1/2 pounds cooked shrimp, peeled, tails removed, and deveined
2/3 cup tomato salsa
2 tablespoons fresh tarragon leaves

1. Bring a medium saucepan of water to a boil. Add the sweet potato pieces and boil gently until tender but still firm, about 8 minutes. Drain in a colander, set aside to drip dry.

2. To assemble, spread about 2 cups shredded lettuce over each tortilla. Arrange about 1/2 cup each of the sweet potatoes and the cucumbers over the lettuce. Mound about 1/2 cup of the shrimp in the center. Sprinkle tarragon leaves over all. Eat while the tortilla is still crunchy.

From: The Well-Filled Tortilla by Victoria Wise and Susanna Hoffman
Adapted from a Bob Terwilliger post in rec.food.cooking on June 4, 2009.