Heat 2 tbsp (30 mL) oil in large saucepan set over medium heat. Stir in ginger and half the garlic; cook 2 min. until fragrant. Add rice. Cook, stirring, 1 min. to coat.
Add 3 ½ cups (875 mL) water, chicken broth, 2 tbsp (30 mL) soy sauce and the rice vinegar; bring to a boil, stir and reduce heat to low. Cover and cook, stirring occasionally, 55 min. to 1 hr. until rice is the consistency of oatmeal. Stir in corn. Cook, uncovered, stirring frequently, 3 min. Slowly pour thin stream of eggs into the rice, stirring constantly about 2 min., until congee is creamy. Cover.
Heat remaining 1 tbsp (15 mL) oil in large skillet set over medium-high heat. Cook remaining garlic 1 min. Add broccolini (if using, broccoli, keep stems intact but trim off tough peels; cut bunches lengthwise into long, thin pieces) and reduce heat to medium. Add 3 tbsp (45 mL) water and remaining soy sauce. Cook, covered, 4 to 5 min. until tender-crisp.
Stir congee and divide into 8 bowls. Top with broccolini, green onions and Sriracha sauce.
Add shredded cooked chicken to simmering congee for added protein