In a medium bowl, combine tomatoes, chile, mango, red onion, and ginger.
Warm oil in a small saucepan over medium-high heat. Add coriander and cook, stirring, until medium brown, about 1 minute. Remove from heat and carefully stir in brown sugar, vinegar, and salt.
Pour warm spice mixture over tomato mixture and let stand 30 to 60 minutes for flavors to develop. Just before serving, stir in green onion.
*Crack seeds using a mortar and pestle, or seal them in a plastic bag and whack with a rolling pin.
Add Heat to Taste: You can control the heat of a salsa by adjusting the heat of the chiles. Slice off the top of each chile, being sure to cut through the ribs and seeds, where the heat-producing compound capsaicin is concentrated. Test the chile's fire by touching the top to your tongue (each chile has a different heat level). Adjust the heat, if you want a milder salsa, by splitting the chile and scraping out some or all of the ribs and seeds. If your skin is sensitive, wear kitchen gloves or hold chiles with a fork-and don't touch your eyes.
Note: Nutritional analysis is per 1/4-cup serving.