Avocado & Pink Grapefruit Salad with Coriander

2 pink grapefruits
2 tbl olive oil
1 tbl minced onion
1 tsp soy sauce
1/2 tsp honey
1/4 tsp sesame oil
1 tsp grated fresh ginger
1 tsp coriander seeds, cracked
2 cups mixed baby greens
1 avocado, halved, pitted, peeled, and sliced

Peel 1 grapefruit and cut it into sections. Juice the other grapefruit and measure out 3 tbl of juice. Whisk the juice with the next 6 ingredients in a small bowl, add salt and pepper to taste. Toss the greens with 2 tbl of the dressing and place on 2 serving plates. Arrange the grapefruit sections and avocado slices on top and drizzle with the rest of the dressing. Sprinkle the coriander seeds on top.