• Most of a bag of radishes that you no longer remember why you bought but apparently only used about 3 of them.
• Half of a blood orange that you have left over from something else, plus however many clementines it takes for the total volume of citrus to be a little more than the total volume of radishes. If you have a whole blood orange, that would probably be better. If you have no blood oranges, or navel oranges instead of clementines, I'm sure any combination of oranges or orange-adjacent fruits will be fine. This is a recipe for using up leftovers, after all.
• 2/3 of a medium onion, sliced. It should be a red onion, really, but if what you have is a yellow onion because it's left over from another recipe that called for 1/3 of an onion (?!?), use that. If you don't have 2/3 of an onion left over from something else, round up to a whole onion. Maybe even a large onion. 
• 1/2 cup of red wine vinegar, or balsamic vinegar, or apple cider vinegar. Plus a few splashes from a bottle of red wine that you happen to have already open when you later discover that you were too skimpy on the vinegar to start with. If you don't have an open bottle of red wine sitting around, increase vinegar to 3/4-1 cup, depending on the amount of onion you're using.
• A handful of toasted pecans that you have left over because you were really bad at eyeballing how many pecans you would need for another recipe and toasted way too many pecans.
• Sugar. About 2 teaspoons, or however much you like.
• Salt, to taste (whatever that means)
• Fresh ground black pepper, also to taste
• Olive or Avocado oil, about 1/4 cup
• A couple squirts of dijon or honey mustard

Directions

1. Place sliced onion in a bowl and pour boiling water over it. Let sit for 5 seconds, then drain and return to the bowl. (I have no idea whether this step is necessary, but it's what the recipe I found when I Googled "quick pickled onions" said to do, so I followed orders.)
2. Combine vinegar, sugar, and a little salt in a small saucepan and heat, stirring, until sugar/salt are dissolved. DO NOT INHALE THE VINEGAR FUMES. If you like to be fancy you can add some other spices, like cloves. I didn't. 
3. Pour vinegar over the onion. When the vinegar isn't enough to fully submerse the onion, add enough red wine to cover. Set aside while you prepare the rest of the ingredients.
4. With a mandolin if you have one or a knife if you don't, slice the radishes into thin rounds and the citrus into slightly thicker rounds. Watch your fingers.
5. Drain the onion, reserving the vinegar. 
6. Combine citrus, radishes, and onion in a large bowl.
7. In a small bowl, combine the oil, mustard, about half as much of the reserved vinegar as you had oil, and generous sprinklings of salt and pepper. Whisk together and taste. Add more vinegar, and maybe more salt and pepper. Repeat until it tastes good. 
8. Pour the dressing and pecans over the salad and fold together gently.
9. Let sit in the refrigerator overnight to allow flavors to meld. Or don't, if planning ahead isn't your thing. Planning ahead obviously isn't my thing, or else I wouldn't have ended up with this hodge-podge of ingredients in search of a way to eat them, but doing major cooking projects after dinner IS my thing, precisely because planning ahead isn't my thing so I frequently end up starving without time to cook and have a microwave burrito for dinner and then figure, now that I'm in the kitchen and no longer starving, I should maybe prepare food for the next day.