Heat the olive oil in a skillet over medium-high heat. Sauté the chopped yellow onion and chopped jalapeño until they start to soften, about 4 minutes.
Add the minced garlic to the skillet and stir for 1 more minute, then turn off the heat and set the pan aside.
In a blender or food processor, combine the drained pinto beans, ground cumin, fine sea salt, and fresh lime juice. Add the sautéed vegetables, secure the lid, and blend until smooth, stopping to scrape down the sides if needed.
Taste the dip and adjust seasoning, adding an extra pinch of salt if desired. For more heat or herb flavor, add a handful of fresh cilantro leaves or a few jarred jalapeño slices and blend again, then transfer the dip to a serving bowl and add any garnishes you like; serve with chips or sliced veggies.
Store leftovers in an airtight container in the refrigerator for up to 5 days; the dip will thicken slightly when chilled.