Heat olive oil in large skillet over medium heat; add onion and sauté until translucent. Add sausage and chopped poblano pepper and cook stirring occasionally until sausage is cooked through. Remove from heat and cool.
Cut twenty 1-inch slices from baguette and arrange in one layer in baking dish.
Whisk eggs and milk; mix in cooked sausage and all remaining ingredients until blended.
Pour egg mixture over bread. Cover and chill overnight.
Preheat oven to 350°F. Bake strata uncovered until puffed and golden, about 40 – 45 minutes.
Let stand 5 minutes before serving.
Serve with sliced avocado, chopped cilantro and/or salsa