Prep the Chicken Cutlets: Slice the chicken breasts horizontally and cut into 12 mini portions roughly the size of your slider buns. Season both sides of each cutlet evenly with garlic powder, onion powder, smoked paprika, sea salt, and black pepper.
Whip the Savory Aioli: In a small bowl, whisk together mayonnaise, grated garlic, fresh lemon juice, chopped herbs, salt, and pepper until smooth. Cover and chill in the refrigerator until ready to assemble.
Cook the Chicken & Toast Buns: Heat olive oil in a large cast-iron skillet or non-stick pan over medium-high heat. Add chicken cutlets in a single layer and cook for 4–5 minutes per side, until deeply golden brown and cooked through (internal temperature reaches 165°F / 74°C). If using cheese, top each cutlet with a small slice of cheese during the last minute of cooking and cover the pan briefly to melt. Slice the brioche slider buns in half horizontally, brush interior tops and bottoms with melted butter, and toast cut-side down in a skillet or oven until golden brown.
Assemble and Secure: Spread a light swipe of savory herb aioli on the bottom half of each toasted brioche bun. Top with a piece of crisp butter lettuce, followed by a warm chicken cutlet with melted cheese. Spread an additional light swipe of aioli on the top bun and place on top to close the slider. Secure each slider by inserting a wooden toothpick or bamboo skewer down through the center. Serve warm on a large platter!