Heat 1/2 cup olive oil in a pan over medium heat. Add sliced garlic and chili peppers, and let them simmer until fragrant.

Add cleaned mussels and shrimp to the pan and stir-fry until they start to cook through.

Pour in 1 can of diced tomatoes and mix well.

Add 1 tbsp butter and season with salt to taste. Stir everything together.

Let the mixture simmer until the seafood is fully cooked and the flavors meld together. Then turn off the heat.

Serve the stir-fried mussels and shrimp in a bowl, drizzle the sauce over, and garnish with chopped green onions.