Prepare quinoa according to the directions in this post. Cool to room temperature or spread on a sheet pan and chill in the freezer for 15 minutes if in a hurry. You can prepare this in advance.
Prepare Corn One Of These Ways:Raw: Cut kernels off the cob—no cooking needed.Charred (Canned or Frozen): Melt 2 tbsp butter in a hot pan. Add corn and cook for 10 minutes, stirring occasionally, until browned. Season with salt and pepper. Let fully cool.Grilled: Brush husked corn with oil, season lightly, and grill at 400°F, turning every 3 minutes until browned (about 12 minutes). Let fully cool, then cut off the cob.
Zest the lime (1/2 teaspoon) and juice it (1 tablespoon). Blend all dressing ingredients until completely smooth. Adjust seasoning to taste.
Chop spinach, cilantro, and green onions. Drain and rinse black beans. Dice avocado. In a large bowl, toss everything together with cooled quinoa and corn.
For the best texture, add the dressing just before serving (see note 2). Shake well, pour about 3/4ths of the dressing (or to taste) over the salad, and toss. Serve immediately.
Video
Notes
Note 1: Grab a can of chipotles in adobo from the international aisle. Use 1 heaping tablespoon (1 pepper with surrounding sauce). Freeze leftovers by placing peppers on a parchment-lined pan, freezing for 1 hour, then transferring to a freezer bag. Store for up to 6 months.Note 2: If not eating immediately, store the dressing and avocado separately. Storage: The salad lasts up to 3 days in the fridge without dressing or avocado. Dressing lasts 1 week in the fridge.