Clean and slice the jalapeños. (Recommend wearing gloves while slicing the peppers)
In a pan: add sugar, water, white vinegar, dried oregano, salt, minced garlic & whisk. Bring up to a simmer (medium-high). Simmer for 2-3 minutes or until the sugar has dissolved.
Add the sliced jalapeños & chopped carrots. Submerge the jalapeños in the liquid. Cook for 3 minutes and remove from the heat source. Let the pickling jalapeños sit in the pan (about 1 hour) or until they are completely cool. Make sure to stir the jalapeños after ~30 minutes.
Transfer the jalapeños & carrots to the jar by placing a small strainer on top of the jar (watch the video for reference). Pour the liquid into the jar. Cover with a lid. If you prefer or are willing to try for more heat or spice; there's no need to strain the liquid or remove the seeds.
Let it sit in room temperature for at least 2 days before eating.