Preheat oven to 400 degrees and line a baking sheet with foil or use a non-stick baking sheet. Thoroughly rinse produce and pat dry. Halve fennel bulb and slice halves into ¼" half-rounds. Core and julienne yellow bell pepper (cut into thin strips). Peel and julienne onion. Mince garlic. Stem and coarsely chop parsley. Halve cherry tomatoes. Rinse sausage and pat dry.

In a medium pan, heat 1 Tbsp. olive oil over medium heat. Once warm, add sausages. Cook 5 minutes per side, or until browned. Save the liquid fat in skillet to sauté vegetables. Transfer sausages to baking sheet and place on top rack of oven to bake for 10 minutes, until blistered and slightly crisp. Minimum internal temperature should be 165 degrees. Remove from oven and tent (cover lightly) with foil to keep warm. Right before serving, slice sausages into 1" thick pieces.

While sausage is in oven, prepare polenta. In a small pot over medium heat, sauté 1 tsp. olive oil and half the garlic until fragrant, about 2 minutes. Add 4 cups water and bring to a boil over high heat. Once boiling, slowly add polenta while constantly whisking to prevent lumps. Reduce heat to low and cook for 5-8 minutes, stirring occasionally. Remove from heat and stir in butter and Parmesan cheese (reserving some for garnish) until fully incorporated. Add a pinch of salt and pepper.

Over medium heat, in the same pan used for sausages, sauté the bell pepper, remaining garlic, onion, and fennel in the remaining fat, stirring occasionally for 5 minutes. Once vegetables are softened slightly caramelized, add tomatoes and sauté for another 2 minutes. Remove from heat. Add a pinch of salt and pepper to season .

Spoon a serving of polenta on the plate. Place vegetables on top of polenta. Add sausage slices on top of vegetables. Garnish with remaining Parmesan cheese, parsley, and a crack of freshly ground black pepper.