In large saucepan, warm olive oil over medium heat.
Add onion and garlic; cook and stir until tender, about 5 minutes.
Add ketchup, brown sugar, and mustard and bring to a simmer.
Drain kidney beans and add with pork and beans to 3–4-quart
slow cooker. Add onion mixture and stir.
Prepare Porcupine Meatballs and freeze all but 12 of them. Brown
the 12 meatballs in the saucepan, about 4–5 minutes total, then
add to bean mixture. Cover and cook on low for 7–8 hours or until
meatballs are thoroughly cooked and tender. Serve immediately.