I liked this, from The Art of Simple Food: Notes, Lessons, and Recipes from a Delicious Revolution

My kids were disappointed…but mainly because when they saw the pink grapefruit sections with avocado they somehow thought it was some sushi salad and then couldn’t get into eating grapefruit when they had thought it was salmon! So set the stage better than I did.

2 grapefruits, peeled, the cut in half, then sliced away from the membranes
2 Tbs grapefruit juice
1 tsp rice vinegar (or white wine vinegar)
salt and pepper to taste
2 Tbs olive oil
2 Haas avocados, peeled and sliced

Here’s how I did the grapefruit. Cut a bit off each end, up until the fruit, so you have a flat end. Stand on one of those ends, then use a sharp knife to cut the peel off from the top to the bottom. Then slice in half horizontally, then cut each section away from the membranes. Take what’s left and squeeze into a bowl and measure out 2 Tbs if you have more than that.

Mix the grapefruit juice with the vinegar, salt, pepper, and olive oil.

Just before serving, cut the avocado in half and remove the pit. Slice the halves down to the skin and then use a spoon to scoop the slices out of the skin and into the bowl with the grapefruit. Whisk together the dressing ingredients and toss with the grapefruit and avocado.

In a small bowl, mix together the grapefruit juice, vinegar, olive oil, salt and peppper. Just before serving, cut up the avocado, mix with the grapefruit, then toss with the dressing.