Start by marinating the shrimp. In a large bowl, mix the cleaned shrimp with calamansi juice and 1 tablespoon of salt. Let this sit for 30 minutes at room temperature.
While waiting, prepare all your ingredients and have them ready beside your stove. This will make cooking smoother.
Heat your pan over medium heat (180°C/350°F). Add the cooking oil and minced garlic. Cook the garlic until it turns light brown, about 1-2 minutes. Add the butter and let it melt completely.
Add your sliced onions to the pan. Cook them until they become soft and clear, about 2-3 minutes. Now add the chopped tomatoes and cook for 5-7 minutes over medium heat (170°C/340°F). Gently press the tomatoes with your spoon while cooking to help them break down.
Take your marinated shrimp out of the bowl and drain off the marinade. Add the shrimp to your pan and cook for just 2 minutes over medium-low heat (160°C/320°F). The shrimp should only turn pink – don't overcook them or they'll become tough.
Add the rice wine to the pan and cook for one minute to let the alcohol cook off. Add your bell peppers, tomato sauce, and Worcestershire sauce. Season everything with chili flakes, cayenne pepper, chili powder, salt, and black pepper to taste. Cook over low heat (150°C/300°F) just until everything is hot and well combined.
Get your sizzling plate very hot. Carefully transfer the gambas onto the hot plate. If you like, top it with a fried egg. Serve right away while the plate is still sizzling and the sauce is bubbling.
Best enjoyed immediately with hot rice. Remember, the sizzling plate is extremely hot - warn your guests before serving.