In a 13-inch saute pan over medium-high heat, add the bacon and olive oil. When the oil heats and the bacon begins to sizzle, add the sweet potatoes and spread out as much as possible to allow the potatoes to rest in the pan in 1 layer. Leave the potatoes to cook until a quick toss reveals browning on the side in contact with the pan, about 5 minutes. Continue to toss and let stand until most sides of the potatoes are golden and the bacon bits are crisp, 3 to 5 minutes longer. Then add the onions, garlic, jalapenos, cumin and season with a nice pinch of salt and a grind or 2 of pepper. Cook the same way, allowing everything to sit in the heat of the pan for a minute or 2. Taste and re-season if necessary.