In a small bowl, whisk together 1/4 cup of white wine vinegar, 1 tablespoon of sugar, and 1/2 teaspoon of salt until dissolved. Add the sliced jalapeño and chopped cilantro, stirring well. Let sit at room temperature while preparing the salad.

In a separate bowl, combine 1/2 cup of thinly sliced red onion with the juice and zest of 1 lime and a pinch of salt. Allow to marinate for about 10-15 minutes, stirring occasionally.

Cut the cucumber in half lengthwise and smash each half gently with a rolling pin. Slice into half-moons and place in a colander. Sprinkle with salt and let sit for 5-10 minutes to draw out moisture.

In a skillet over medium heat, sauté 2 minced garlic cloves in 1 tablespoon of olive oil until golden. In a blender, combine sautéed garlic, pickled jalapeños, juice of 1/2 lime, 1 tablespoon of vinegar, 1 tablespoon of agave syrup, 2 tablespoons of miso, and cilantro. Blend until smooth.

In a large bowl, combine drained cucumbers, cannellini beans, chickpeas, and marinated onions. Pour dressing over and toss gently until coated.

Slice an avocado and mash with salt. Spread on tostadas and top with the bean salad and pickled jalapeños.

Store salad and pickled jalapeños in airtight containers in the fridge separately for up to 4 days. Combine when ready to serve.