1. In a medium saucepan, heat 2 tablespoons olive oil over medium heat. Add button mushrooms and cook, stirring occasionally, until beginning to soften. Season with salt and pepper to taste.
2. Add cream and chicken broth to mushrooms and bring to boil. Reduce to a simmer and cook for 20 minutes. Cover mixture and continue to simmer for 20 minutes longer. Remove from heat and let stand covered for 20 minutes. Strain mixture, discarding mushrooms and reserving cream mixture.
3. Meanwhile, in a small skillet, heat 1 tablespoon olive oil and butter over medium heat. Add Portobello mushrooms and cook until beginning to soften. Remove from heat.
4. To serve: Warm cream mixture if necessary. Divide between bowls and top with Portobello mushrooms, pecans and chives. Serve immediately.