Place 18 slices on baguette on a parchment-lined baking sheet.
Put 1 Tbsp olive oil in a small bowl and brush oil over each baguette slice.
Broil until slices turn slightly brown. This will be a quick 1 -2 minutes.
Shrimp (can be made earlier in the day)
Heat 1/2 Tbsp olive oil in a non-stick pan over medium heat.
Add shrimp, salt, pepper, and red pepper flakes.
Cook shrimp until it turns pink and curls, about 4 minutes
If you are not assembling the appetizer at this point, refrigerate the shrimp and take out about 30 minutes in advance to let it get to room temperature.
Cream Cheese Mixture
Place cream cheese, dill and red onions in a small bowl and stir.
Assembly
Place baguette slices on a platter. Spread the cream cheese mixture over each piece.
Next place a shrimp, avocado slice and sun-dried tomato over the cream cheese and serve.