Place the pork in a medium bowl, seasoning all over with kosher salt. Sprinkle the rice flour over top, tossing to lightly coat the pork in the flour. Set aside.
Combine all listed ingredients in a medium bowl. Whisk to combine. Set aside, or store in an airtight container in the refrigerator for up to 1 week.
Add 1 tablespoon of the olive oil to a large skillet over medium-high heat. Once hot & shimmering, add in the bell pepper, onion, tomatoes, & garlic. Cook, stirring constantly until barely softened, about 1 minute. Carefully transfer vegetables to a large plate or bowl & set aside.
Return the skillet to medium-high heat. Add in the remaining olive oil. Once hot & shimmering, add in the pork, shaking off excess rice flour before adding it to the pan. Cook the pork until deeply browned, about 90 seconds per side.
Pour the sweet & sour sauce into the skillet with the pork. Increase heat to high. Cook, stirring often, until the sweet & sour sauce thickens slightly, 2-3 minutes. Add the vegetables back into the pot. Stir to combine & cook until warmed through.