Prepare spice rub by combining the chili powder, red pepper and salt. Rub over pork shoulder 1 hour before cooking or the night before. Refrigerate meat until ready to cook.
Place the pork in the slow cooker with the garlic. Pour stock over the meat. Set on low and cook for 5-6 hours.
Remove lid and break up meat. Add diced tomatoes, beans and escarole to slow cooker with the greens placed on the top to steam. Continue to cook for 1 hour.