Bring a large bot of salted water to a boil, then add the sweet potatoes. Simmer just until fork tender, about 10 to 15 minutes depending upon the size of your potato chunks. Drain, gently and quickly rinse with cold water, then set aside.
If necessary, cook the bacon according to one of my easy methods listed below. Once cool, crumble it into a large bowl. Add the celery and green onions.
Prepare the mustard dressing: In a small bowl or large measuring cup, whisk together the jalapeño (or fresno chile), mustard, garlic, vinegar, olive oil, salt, and pepper.
Add the sweet potatoes to the bowl with the bacon, drizzle with the dressing, then toss gently to combine. Taste and season with additional salt/pepper as desired. Serve warm, chilled, or at room temperature.
TO STORE: Store leftovers in the refrigerator for up to 4 days.
TO REHEAT: No reheating is necessary. Enjoy this sweet potato salad cold or at room temperature. However, I have warmed up leftovers as a side at dinner and they were delish. If you want to try this sweet potato salad warm, reheat it in a microwave for several minutes until heated through.