For The Red Cabbage Coleslaw For The Tostadas

1. Turn the oven to 375°F (190°C) to preheat it.
2. Toss the cabbage, green onions, and cilantro in a large bowl.
3. In another large bowl, make a dressing by whisking together the lime juice, apple cider vinegar, and sugar. Add salt and pepper for flavor. Mix the dressing into the cabbage mixture. Let it rest for 15 to 20 minutes, tossing it every now and then.
4. Put the cucumbers in a medium baking dish and spread them out. Brush with the melted butter and sprinkle with the sliced shallot. Season with salt and pepper to taste.
5. Bake the cucumbers for 45 to 50 minutes, or until they are soft. Toss them every once in a while.
6. Mix together the mayonnaise, sriracha, and paprika in a small bowl.
7. Build the tostadas: Put some cucumbers, slaw, spicy mayonnaise, and cilantro on each one. Serve lime wedges on the side.