Rinse spinach leaves, pat dry and remove stems. Cut the tomato into circles 7-8 mm thick. Mix cream cheese with mayonnaise.
Cut the sausage into slices 10-12 mm thick. Heat vegetable oil in a frying pan, add sweet chili sauce, mix. Heat the sausage slices in this mixture.
Cut hamburger buns in half and toast, cut side down, on the grill or in the oven, or in a dry skillet.
Place the spinach leaves on the bottom half of the bun and top with the cream cheese and mayonnaise mixture. Close up with a tomato. Put a hot slice of sausage on the tomato, then a slice of cheese. Cover with the other half of the bun.