In a large sauté pan over medium heat add the garlic and onions. Once they are translucent, add the roughly chopped spinach and diced tomatoes. Let everything soften in the pan.
Once the spinach is wilted, add the salt, pepper, cream cheese, 2% milk and parmesan cheese. Stir until well combined.
Next, you’ll add the Dijon mustard and drained tuna. Fold all of the ingredients together until they are well combined.
Turn on the broil setting on your oven.
While the broiler is heating, place 5-6 pieces of lightly toasted bread on a baking tray.
Spoon the tuna melt mixture onto the bread. Top with fresh tomatoes slices and some shredded mozzarella cheese.
Broil for 1-2 minutes or until the cheese is golden brown and bubbly.
Serve immediately and enjoy!