In a small mixing bowl, whisk together equal parts vinegar, sugar, and salt until dissolved. Add sliced jalapeños and chopped cilantro, and let marinate for at least 15 minutes.

Slice red onion and massage with lime zest, lime juice, and salt for 2-3 minutes until softened.

Slice cucumbers in half, crack them lightly, cut into pieces, sprinkle with salt, and let sit for 5 minutes.

Heat oil in a saucepan, sauté minced garlic until golden, then blend with marinated jalapeños, lime zest, vinegar, agave, miso, remaining cilantro, and salt until smooth.

In a bowl, combine marinated onion, cucumber pieces, chickpeas, and cannellini beans. Pour in dressing and toss gently.

Spread mashed avocados on tostadas, top with the salad, and garnish with pickled jalapeños.

Store in separate airtight containers for up to 4 days.