Thinly slice garlic (1/4 cup) and serrano pepper. Finely chop parsley (about 1/2 cup). Juice 2 lemons (1/4 cup); slice remaining 1 lemon into wedges. Cut baguette into 1 1/2-inch slices.
Preheat large saute pan on high for 4-5 minutes. Add oil, garlic, and serrano peppers; cook 30-60 seconds, stirring often, until light golden brown. Add shrimp and cook 2-3 minutes, stirring occasionally, until pink and opaque.
Stir in parsley, lemon juice, and salt. Serve immediately with baguette slices and lemon wedges.
