Make the sandwiches and serve

• Spread butter on each sourdough slice and sprinkle with sesame seeds. Heat large nonstick skillet over medium-high heat. Add 2 slices of sourdough, butter side down. Sprinkle just ¼ the cheddar on each slice and add as much jalapeño and kimchi as you’d like. Top with remaining cheddar and close sandwiches with remaining sourdough slices, butter side up. Continue to cook until sandwiches are golden brown, 3 to 4 minutes per side. Cut sandwiches in half and serve with extra kimchi.