Prepare the dressing first for the flavors to sit and blend. Mix the garlic, lime juice, and water together, then slowly add the fish sauce alternating with the agave, tasting in between. The lime flavor should be noticeable, but not sour and the fish sauce should be noticeable but not overbearing. Do not over-sweeten since there will be some sweetness from the mango. Add sriracha slowly to taste.
Peal the mango and, using a mandoline, cut the fruit into strings. Bring water to a boil and drop the raw shrimp and immediately turn off the flame. Remove from the water as soon as it is uniformly pink and opaque. This will ensure the shrimp is tender and juicy. Cut the shrimp as indicated. Place in the bowl with the mango and with the other prepared salad ingredients. Pour about half of the dressing in and toss. If you need more dressing to fully coat the ingredients, add until satisfied.
Allow the salad to sit for about 5 minutes for the dressing to set, then serve. Yields 4 small side salads or two lunch portion salads.
Garnish with more sriracha if desired.