Cut each lobe off the mango lengthwise, avoiding the pit in the center.
Take one lobe, and push the edge of a tall glass in between the mango flesh and peel. Push down until mango flesh has detached from the peel and fallen into the glass.
Repeat with second lobe.
Cut mango flesh into cubes (you should have about ½ cup).
Put mango cubes into a blender and add rice vinegar, orange juice, ginger, and chili powder.
Blend until smooth, scraping down sides as necessary.
With blender running, pour olive oil into the top opening of the blender. Blend until combined.
Unless you are using your dressing for a dip, add 1 tablespoon of water at a time to loosen up dressing (up to 3 tablespoons).
Season with salt and pepper, to taste, and serve.
Notes
Make-Ahead: Store in a covered jar in the refrigerator for up to 5 days. You can also freeze mango dressing, but it may separate when defrosted. If it does, whisk vigorously or pop into blender and blend until it comes together. Note: If your mango is particularly fibrous, put dressing through a fine-mesh sieve, pressing down on any mango solids. Flavor Options: Try curry powder instead of chili powder. Or add extra heat with red pepper flakes or chopped jalapeños or habanero (if you’re brave!). You can also make a more citrusy version by replacing the vinegar with lemon or lime juice, and adding zest as well. You can add herbs as well like fresh basil or cilantro. For an even creamier version, try blending in some yogurt (obviously it will no longer be vegan if you do that).