Add sorghum, water, and a pinch of salt to a large saucepan and bring water to boil. Once the water has boiled, bring water to a low simmer and let the grains cook for 50 minutes, half covered. The sorghum is cooked when grains are soft but with some chew. Drain excess water.
When the sorghum is nearly done, prepare the pesto. Throw all pesto ingredients into a high-speed blender or food processor and blend until smooth. Add a salt, if desired.
Toss sorghum with 1/4 cup of pesto. Save remaining pesto for another pasta or pizza dish. Mix in the plum tomatoes, microgreens, green onions, chopped parsley, and toasted pine nuts. Season with salt and pepper.
Best served immediately. Refrigerate leftovers in an airtight container for 3 to 4 days.