Easy Tuna Melts

Bahan-bahan (2 porsi)

• 1 ripe tomato (sliced)
• 2 english muffins (halved)
• 2 ounces cheddar cheese (shredded)
• 1 (5 ounce each) can tuna ( in water, drained)
• 1 rib celery (finely diced)
• 1 g reen onion (sliced)
• ⅓ cup mayonnaise
• 1 teaspoon Dijon mustard
• ½ teaspoon fresh lemon juice
• salt and black pepper (to taste)