Heat the grill/broiler to medium/high. Heat the olive oil over a medium heat and add the onion. Season well and cook for 5-10 minutes until softened then add the garlic and spinach and cook for a couple more minutes until the spinach is wilted.
Tip into a large bowl and add the artichokes, cream cheese, lemon juice and dijon mustard. Toast the bread slices in a toaster or on a grill.
Place the toast on a lined baking sheet and split the artichoke mixture between the toast slices. Top with a quarter of the grated cheese then place under the grill until the cheese is melted and bubbling. Serve.
Notes
Nutrition information is an estimate and will vary depending on the exact ingredients used.