In a medium saucepan over medium heat, saute onion, add in tomato sauce, cream cheese, and yogurt.
Once everything has melted together and the cream cheese has no lumps, add in the gelatin and bring to a simmer for 1 minute, small boil, and stir for that one minute for the gelatin to incorporate fully.
Add in the lemon juice, and old bay seasoning and give it a taste, add additional salt if desired.
Add any additional item you'd like, 2 cups finely chopped fresh spinach, hot sauce, and crushed red pepper flakes for it to infuse flavor while the dip is hot.
Pour into serving dish if serving hot.
Pour the hot dip into a mold (a decorative dish with design or shape) fun options, a football or crab, lobster, or fish. Place wax paper over the dip and place it in the fridge for 6 hours or until completely cold. Then turn out onto a serving plate. Serve with toasted baguette, crackers, or vegetables.