Spicy Pork with tomatoes

6 tablespoons vegetable oil, divided (plus more if needed) 1 1/2 cups chopped onions 1 cup diced carrot (1/2-inch dice) 2 tablespoons minced serrano peppers 3[...]

2 tablespoons olive oil 3 lbs boneless pork shoulder 1 medium onion , diced 4 cloves garlic , peeled & crushed 2 tablespoons crushed red pepper flakes 2[...]