Preheat a grill until smoking hot. Brush the corn with some olive oil and grill, rotating the ears, until all the sides are charred, 2 to 3 minutes per side. Remove from the heat and cool. Use a knife to shave off the kernels and put them in a large salad bowl.
Brush the beet
slices with some olive oil, season them with some salt and pepper and grill
for 3 minutes on each side. Transfer the beets to a cutting board, cut each round into quarters, and add them to the salad bowl.
Put a fine-mesh strainer over a medium bowl. Halve the prickly pears
and scoop out the fruit into the strainer
. Press the fruit to release as much juice as possible. Discard the seeds and pulp. Whisk
the vinegar and 2 tablespoons of olive oil into the juice to combine. Season with salt and pepper.
Add the greens
, onion and vinaigrette
to the corn
and beets. Toss to combine and serve.