Pour out artichoke hearts into a colander placed in the sink and let them drain well.While they drain, slice the green onions and crumble the feta.Spray the slow cooker insert well with non-stick spray.Remove artichoke hearts to the cutting board and pour out the roasted red peppers into the colander to drain.Cut the artichoke hearts into fairly small pieces (quarters, or smaller if they’re large) and put them in the bottom of the slow cooker insert.Cut the drained red peppers into pieces about 1/2 inch square and put them into the slow cooker.Add the green onions to the slow cooker.Beat the eggs until whites and yolks are completely combined and then pour eggs over the vegetables in the slow cooker.Use a fork to gently stir, so the artichoke pieces, red pepper pieces, and sliced green onions are well distributed. Sprinkle the crumbled Feta over the top and season with Spike Seasoning and freshly-ground black pepper.Cook on low for 2-3 hours or until the eggs are as firm as you’d like them and the cheese is melted. (I cooked mine about 2 1/2 hours, but I think the Ninja might cook a little hotter than some other slow cookers. Cut into pieces while the frittata is still in the slow cooker. Serve hot, sprinkled with chopped parsley to garnish if desired.